can power conditioners cause lcd displays to malfunction free sample

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Make sure you"re getting the most out of your home theater equipment with the MAX 5400-PM from Panamax. Voltage Regulation Improve system performance and prolong equipment life by providing a consistent level of optimal power to your equipment. Improves Picture and Sound Quality Level 4+ power cleaning and filtration eliminates common symptoms of contaminated power (including loss of detail, pops, hisses, hums and visual artifacts) and allows you`re a/V equipment to perform up to its full capability. Monitors Incoming Line Voltage and Provides a Visual Indication of Power Level Panamax"s patent pending AVM circuitry continuosly monitors the incoming power as displayed on the digital voltmeter. In case of an undervoltage or an overvoltage, a flashing lightning bolt will be displayed in red in the voltmeter, and power to the connected equipment is automatically turned off if either of these conditions is detected. When voltage returns to a safe level, power to the equipment is automatically reconnected. Reduces Cross-Contamination Between Components The M5400-PM is designed to provide noise isolation between 5 isolated outlet banks (including 1 bank with 2 high current outlets) so that any noise created by an A/V component cannot contaminate the power going to equipment plugged into another outlet bank.

Level 4+ Power Cleaning and Linear Filtration eliminates common symptoms of contaminated power (including loss of detail, pops, hisses, hums and visual artifacts) and allows your A/V equipment to perform up to its full capability. Panamax"s patent pending AVM circuitry continuously monitors the incoming power as displayed on the digital voltmeter. In case of an undervoltage or an overvoltage, a flashing lightning bolt will be displayed in red in the voltmeter, and power to the connected equipment is automatically turned off if either of these conditions is detected. When voltage returns to a safe level, power to the equipment is automatically reconnected.

The M5400-PM is designed to provide noise isolation between 5 isolated outlet banks including 2 high current outlets so that any noise created by an A/V component can not contaminate the power going to equipment plugged into another outlet bank.

Improve Your Picture and Sound Quality While Protecting Your Home Theater InvestmentAll the features you need to keep your system running clean and safe

Voltage RegulationRegulates the output voltage on Banks 1-4 to 120 VAC ± 5 VAC. This is accomplished through two boost stages and one buck stage of voltage regulation. In Boost Stage 1 the voltage is boosted in the 109-119V range, while Boost Stage 2 boosts the voltage in the 100-109V range. The Buck Stage acts to reduce voltage in the 125-136V range. LiFT Technology EMI/RFI Noise Filtration : Your audio/video components are constantly being bombarded by electromagnetic interference (EMI) and radio frequency interference (RFI) through their AC power source. This contaminated power can affect audio/video equipment and will degrade the overall performance of your entire system. Common symptoms of contaminated power include loss of picture detail, dull colors, pops, hisses, hums and visual artifacts.Automatic Over and Under Voltage Protection (AVM)Panamax"s patent pending power monitoring circuitry constantly monitors the AC line voltage for unsafe voltage conditions such as momentary spikes or prolonged over-voltages and under-voltages (brownouts). These unsafe conditions pose a very dangerous threat to all electronic equipment within the home. If the MAX 5400-PM senses an unsafe power condition, it will automatically disconnect your equipment from the power to protect equipment from damage.Once the voltage returns to a safe level, the M5400-PM will automatically reconnect the power. When subjected to a 6,000V (open circuit voltage) / 500A (short circuit current) surge, the M5400-PM limits its voltage output to less than 330V peak, UL"s best rating. If the magnitude of the surge is greater than the capacity of the surge protection components, the M5400-PM"s Protect or Disconnect Circuitry will disconnect your equipment in order to protect it. The M5400-PM will need to be repaired or replaced by Panamax if this occurs within the product’s 3 year warranty.Five Isolated Outlet BanksThe M5400-PM is designed to provide noise isolation between the outlet banks so that any noise created by A/V components plugged into the M5400-PM cannot contaminate the power going to equipment plugged into the other outlet banks of the M5400-PM.Sequential Startup/ShutdownComplex audio/video systems may be susceptible to voltage transients generated internally at start-up/shutdown if all of the equipment is powered on or off at the same time. This can cause speaker "thumps" which are not only annoying but can also damage the speakers and/or trip product circuit breakers. The M5400-PM is designed to eliminate these transients by providing a "start-up" delay for the High-Current outlets and a "shutdown" delay for the Switched Outlet Banks. This minimizes in-rush current issues by allowing the components plugged into the Switched Outlet Banks to power-up and stabilize before any amplifiers and powered sub-woofers are turned on. This sequence is reversed during shutdown. The amplifiers and powered subwoofers turn off, their power supplies drain, and then the equipment plugged into the Switched Outlet Banks are turned off.USB Charger, LAN, and Gaming PortsThe M5400-PM features a front panel convenience charger for mp3 players, cell phones, video game controllers, and other small electronics. (NOTE: Some devices may not be compatible with this USB charger.) Add to this an easy-to-access LAN port pass-thru from the rear panel to the front panel for online gaming and a convenience outlet located on the front panel, perfect for gaming systems and other electronics.Find out more about the M5400Voltage Sense TriggerThe M5400-PM voltage sense trigger input uses a standard 3.5mm (1/8") mini-mono plug. This feature provides an ON/OFF trigger for the M5400-PM using a Direct Current voltage signal. Many components such as pre-amplifiers and receivers have a DC trigger built in, and will transmit a constant power signal when turned on and in use. The presence of this power signal will turn on the M5400- PM"s switched outlets. When the source component is turned off, the voltage trigger signal is also turned off and the M5400-PM"s shutdown sequence is initiated. An AC Adapter of the appropriate voltage plugged into a switched outlet may also be used if a DC trigger is not built in.Protection for Cable/Satellite/Antenna as Well as LAN and Telephone LinesCoaxial protection circuits achieve optimum signal quality from our new coaxial protectors that have the smallest signal loss on the market - less than 0.5 db of attenuation from 0 MHz to 2.2 GHz. Our upgraded coaxial protection has been specifically designed to virtually eliminate signal loss. The clamping level of 75V will meet the demands of both cable and satellite voltage while minimizing exposure to damaging spikes and surges.

Digital video recorders and satellite TV receivers require a telephone line connection for TV show scheduling and/or Pay-Per-View services. The M5400-PM also provides surge protection for this line. One pair of RJ-11 telephone jacks is provided for this. The circuitry utilizes auto-resetting PTCRs and solidstate SIDACtors for reliability and unsurpassed protection. The clamping level of the M5400- PM"s telephone protector is 260 volts. This will allow typical ring voltage (90-130VAC) and operating battery voltage (-48DC) to pass through the circuit and still protect the modem in your satellite receiver from damage.

Protection circuits for 10/100 baseT Ethernet lines. Incoming LAN line MUST be plugged into the LINE jack. Patch cord to the equipment MUST be plugged into the EQUIP jacks. 1 LAN jack goes to the front panel output jack. 8 wire protection, 52V clamping.The M5400 provides reliable power protection for mid-sized home theater systems

The Panamax Family of Power Management Solutions for Home Theater ApplicationsSurge Protection & AVMVoltage RegulationHome Theater ApplicationsLinear FiltrationIsolated Outlet BanksTotal OutletsHow this benefits your home theater system:Protects equipment against momentary spikes and prolonged over/under voltages by disconnecting the power and reconnecting it when safe power returns Improves system performance and extends equipment life by providing a consistent level of optimal power to your equipment Just a few examples of electronic equipment pieces that need power management protection Improves Picture and Sound. Provides concert-quality sound and theater quality video Isolating outlet banks from one another prevents noise contamination between components Each model offers a mix of always-on, switched, and high-current outlets to meet the needs of every systemM7500-PROIncluded (The Ultimate)*

*with regulation Included 50” and above TV screen size, Media Servers, Home Automation Systems, Audio/Video Receivers (AVR), Amplifiers, DVD players, Video Game Consoles, Powered Speakers, Subwoofers EMI/RFI Banks 1 - 4 100 db, 100 KHz – 2 MHz

*with regulation Included 50” and above TV screen size, Media Servers, Home Automation Systems, Audio/Video Receivers (AVR), Amplifiers, DVD players, Video Game Consoles, Powered Speakers, Subwoofers EMI/RFI Banks 1-4: 80db, 100KHz, -2MHz

Bank 5 (Hi Current): 60db, 100KHz -2MHz 5 11M5300-PMIncluded (Best) Not included 50” and above TV screen size, Receivers, Amplifiers, DVD players, Video Game Consoles, Powered Speakers, Subwoofers EMI/RFI Banks 1-4: 80db, 100KHz, -2MHz

Bank 5 (Hi Current): 60db, 100KHz, -2MHz 5 11M5100-PMIncluded (Better) Not included 19" and above TV screen size, Receivers, DVD players, Video Game Consoles, Powered Speakers, Subwoofers EMI/RFI Banks 1-2: 80db, 100KHz, -2MHz

Bank 3 (Hi Current): 60db, 100KHz, -2MHz 3 11M4300-PMIncluded (Good) Not included 19" and above TV screen size, Receivers, DVD players, Video Game Consoles, Powered Speakers, Subwoofers EMI/RFI Bank 1: 60db, 100KHz, -2MHz

What"s in the Box(1) M5400-PM Power Management Component (1) Coaxial cable, 36 inches (1) Telephone Cable, 48 inches (1) LAN cable (CAT-5), 48 inches (1) Rack mount kit

Eaton offers a comprehensive range of power conditioning (PC) products designed to address a wide variety of common power quality issues, including voltage regulation, sag protection, harmonic isolation and attenuation. Before determining the optimal device for your facility, it is helpful to gain a general understanding of the specific power quality issue you are facing, as well the key factors to consider when selecting a power conditioner for your application.

A power conditioner is a general term to describe a piece of equipment that can be used to improve a system’s power quality. While at times used to refer specifically to an uninterruptible power supply (UPS), that is only one of many products that fits the term. Other products include voltage regulators, noise attenuating transformers and active harmonic filters.

The Institute of Electrical and Electronics Engineers (IEEE) defines power quality as “powering and grounding electronic equipment in a manner that is suitable to the operation of that equipment and compatible with the premise wiring system and other connected equipment.” For owners and operators of electronic equipment, thisdefinition can be expanded to include factors that impact the overall lifespan of equipment; for example, the damaging and life-reducing effects of harmonics.

An effective power conditioning solution can vary dramatically among different organizations and facilities. Specific power quality issues present within the electrical system, business goals and load profiles are among the considerations when assessing or configuring a solution. The “black box” approach is seldom an electrically suitable or cost-effective solution. Engaging in a power factor study or mini–power factor study can go a long way toward identifying problems and implementing an optimal solution.

There are two components of voltage variation ── magnitude (how far voltage has deviated from nominal) and duration (the amount of time over which the deviation occurs). Either of these factors can result in a variety of dangerous power quality conditions, including overvoltage, surges and sags. Overvoltage occurs when the voltage exceeds nominal for a sustained period of time, either for multiple cycles or lasting indefinitely. A sub-cycle overvoltage event is referred to as a surge, which is categorized as a brief overvoltage or disturbance on a power waveform that can damage, degrade or destroy electronic equipment. A sag, on the other hand, is a sustained condition of decreased voltage below nominal for multiple cycles. A sag that drops to zero for any amount of time is referred to as an outage.

Incoming voltage to facilities can vary, as can the voltage to an individual piece of equipment. The typical magnitude of a good voltage source is +/-5% of the nominal voltage (208, 240, 480, etc.). While electric utility companies must meet specific requirements for nominal voltage, those conditions often fall outside of a +/-5% tolerance. Furthermore, the operating tolerance of many devices is often even tighter.

Harmonics ── defined as the content of the signal whose frequency is an integer multiple of the system"s fundamental frequency ── causes a distortion in the waveform shape of the voltage and current, increases current level and changes power factor supply. This, in turn, can result in a variety of damaging power quality issues. Nuisance operation of fuses and breakers, insulation deterioration and audible noise in electrical equipment can all be early indicators that harmonics is present.

Harmonics can lead to equipment malfunction and failure. Notching ─ a voltage waveform distortion resulting from short-duration high current pulses ─ causes control malfunction and regulator mis-operation, while increased current can lead to overheating and failure of transformers, motors and cables. There are also economic considerations where harmonics are concerned. Some organizations will intentionally oversize equipment in an attempt to accommodate harmonics, losses and inefficiencies. Others may not be able to install capacitors they need avoid power factor correct (PFC) penalties, and may require more expensive detuned filters or active VAR injectors.

A system guideline for setting limits on voltage and current distortion, the intent of IEEE-519 is to ensure that utility companies provide a “clean” voltage and limit harmonic current from customers, who must protect their infrastructure and limit disruptive impact on critical loads. This is important because harmonics affect multiple entities. For instance, harmonic polluters feed the distortion from their facility bank onto the electrical grid, with other nearby customers able to see the effects of that distortion within their own facilities. Equipment manufactures specify the levels of harmonic distortion at which their equipment is suitable to operate (typically an upper limit), but if a facility’s distortion levels are too high, that equipment may not operate properly or could be damaged. Manufacturing equipment to operate at higher distortion levels ─ if even possible ─ would entail a significant expense.

Current distortion causes voltage distortion, which is created by pulling distorted current through an impedance. The amount of voltage distortion depends on system impedance and the amount of distorted current pulled through the impedance. If either increase, voltage total harmonic distortion (VTHD) will increase.

Analog signals need to be correctly "prepared" before they can be converted into digital form for further processing. Signal conditioning is an electronic circuit that manipulates a signal in a way that prepares it for the next stage of processing. Many data acquisition applications involve environmental or mechanical measurement from sensors, such as temperature and vibration. These sensors require signal conditioning before a data acquisition device can effectively and accurately measure the signal.

For example, thermocouple signals have very small voltage levels that must be amplified before they can be digitized. Other sensors, such as resistance temperature detectors (RTDs), accelerometers, and strain gauges require excitation to operate. All of these preparation technologies are forms of signal conditioning.

Signal conditioning is one of the fundamental building blocks of modern data acquisition(aka DAS or DAQ system). The basic purpose of a data acquisition system is to make physical measurements. They are comprised of the following basic components:

Data acquisition systems need to connect to a wide variety of sensors and signals in order to do their job. Signal conditioners take the analog signal from the sensor, manipulate it, and send it to the ADC (analog-to-digital converter) subsystem to be digitized for further processing (usually by computer software).

As the name implies, they are in the business of conditioning signals so that they can be converted into the digital domain by the A/D subsystem, and then displayed, stored, and analyzed.

After all, you cannot directly connect 500V to one of the inputs of an A/D card - and thermocouples, RTDs, LVDTs, and other sensors require conditioning to operate and to provide a normalized voltage output that can be input into the A/D card.

In the world of electric sensors, we need different types of signal conditioning circuits in order to properly condition signals coming out from those sensors. Today common types of signal conditioners are:

The best signal conditioners provide electrical isolation between the inputs and their outputs. Isolation reduces noise, prevents ground loops in the measuring chain, and ensures accurate measurements.

Sometimes also referred to as galvanic isolation, electrical isolation is the separation of a circuit from other sources of electrical potential. This is especially important with measuring systems because most signals exist at relatively low levels, and external electrical potentials can influence the signal greatly, resulting in wrong readings. Interfering potentials can be both AC and DC in nature.

For example, when a sensor is placed directly on an article under test, (e.g. a power supply) which has potential above ground (i.e., not at 0V), this can impose a DC offseton the signal of hundreds of volts. Electrical interference or noise can also take the form of AC signals created by other electrical components in the signal path or in the environment around the test. For example, fluorescent lights in the room can radiate 400 Hz which can be picked up by very sensitive sensors.

This is why the best data acquisition systems have isolated inputs - to preserve the integrity of the signal chain and ensure that what the sensor outputs is truly what has been read. There are several kinds of isolation techniques employed today.

It is important that isolation is in place not just from channel to ground, but also from channel to channel. Excitation lines should also be isolated where necessary. A comprehensive isolation system prevents damage to the systems from excessive voltage and avoids ground loops and wrong measurements.

As one example, signal conditioners of Dewesoft’s SIRIUS DAQ systems provide isolation of 1000V (the HV high voltage module is additionally rated CAT II 1000V).

The best signal conditioners are fully adapted to the sensors that they are intended to be used with. At the most basic level, this includes the use of the appropriate connector(s) for these sensors.

Voltages are typically handled with BNC connectors (up to 50V), and safety type banana plugs above that. For voltage output sensors that require sensor supply by the signal conditioner, a multi-pin connector is used, such as compact and high-reliability LEMO connectors, or less-expensive (but larger) DB9 (DSUB-9) connectors. This is why most manufacturers, Dewesoft included, make their voltage signal conditioners available with a variety of connector types.

Strain gauges are usually sold with bare wires because there is no industry standard for the multi-pin connectors that should be used, or for the wiring method that the engineer will choose (3-wire, 4-wire, sense lines or no sense lines, etc). The most commonly employed multi-pin connectors used in strain gage applications are compact and high-reliability LEMO connectors or less-expensive (but larger) DB9 (DSUB-9) connectors.

It should be mentioned that for data acquisition systems that are permanently mounted in an industrial measurement environment, these requirements are different. Unlike a typical data acquisition system that is going to be moved around and used for a variety of applications, these systems are “fixed” and do not change. Fixed or embedded systems are typically outfitted with screw terminal block connectors, which are very efficient and low-cost. They do not have to be rugged or tamper-proof since they are locked away.

The ability to select the proper measuring range for a given sensor is the most basic essential function of a signal conditioner. In order to get the best possible results from their measurements, engineers must be able to set the voltage level (or gain in general) of the conditioner.

For example, if you are trying to measure a voltage that spans from ±2.5mV (±0.0025V), but your conditioner only has a ±50V range, your signal will be extremely small within the resulting gain aperture to the point of being unusable. Similarly, if your voltage is going to span ±100V but your only range is ±50V, half of the signal will be clipped by the conditioner and will never be measured.

Aside from setting the input gain, perhaps the next most important function of a signal conditioner is to provide some manner of filtering. At the very least, a two or four-pole low-pass filter is often needed to suppress or reduce electrical noise, which can get into the signal from the testing environment.

One kind of filtering must be done in hardware, before the ADC process: anti-aliasing filtering. This is a special kind of filtering that prevents wrong readings that can happen when the sample rate is set too low compared to the frequency content of the signals being measured. Anti-aliasing filters (AAF) prevent wrong readings by automatically adjusting the front-end filter according to the selected sample rate. There are more details about AAF in the article called “What Is An A/D Converter?”

Virtually all other filtering can be done either in hardware or in software. For example, Dewesoft DAQ systems provide hardware filtering wherever it might be required by the application, for example, the high-pass hardware filters in their CHG (charge amplifier) and ACC (IEPE amp), which are useful for AC coupled accelerometer outputs prior to signal integration.

Other hardware filters are provided within Dewesoft DAQ hardware. But in addition, a powerful suite of software filters are provided for each channel. In fact, software filters can be applied non-destructively in Dewesoft DAQ systems, before or after recording (or both). This allows engineers to capture both the raw signal and one or more filtered copies of the signal, and compare them (as shown in the diagram above where a raw and filtered signal can be overlaid on the same graph).

Each signal conditioner must be perfectly adapted to the sensor with which it will be used. Sensors have vastly different requirements based on their operating principles, which the conditioner must be adapted to.

For example, a strain gage (aka strain gauge) signal conditioner must provide excitation voltage to the strain gage sensor. And since engineers use anywhere from one to four gages when making strain measurements, the conditioner needs to be adaptable to handle a quarter, half or full-bridge configuration.

Strain gages require perhaps the most complex setup in the world of signal conditioning, therefore the best conditioners provide a wide range of features including bridge completion, shunt cal, sense line hookup to suppress self-heating and sensor line resistance changes, and more.

Hard requirements such as isolation, sensor supply, input gain, and anti-aliasing must be done in hardware. Most filtering (except for anti-aliasing filtering) and linearization can be done in software.

If we look at voltage measurement, it would seem that this would be the easiest task because the signals already exist as a voltage. However, the voltage can span from very small potentials in the billionths of volts, up to tens of thousands of volts. It can also exist as an alternating current (AC) or direct current (DC).

Voltage potentials (electric potential) can exist far above the ground, or be centered around 0V. The challenges and therefore the processes are essentially the same as with any other physical phenomena that we want to measure. Small voltages must be amplified to a nominal digitizing level (typically ±5V). Galvanic isolation is often needed to prevent cross-talk and ground loops which can destroy the integrity of the measurement by introducing wrong values and offsets.

It is sometimes required to AC couple a voltage to remove the DC component or provide low or high-pass filtering in order to achieve certain measurement goals.

The SIRIUS LV DAQ module from Dewesoft is available with a variety of connector types to suit the application: BNC, safety banana jacks, DSUB9, and others upon request. For more information visit the SIRIUS tech specs page.

Large voltages must be stepped down to the nominal digitizing level. There are sensors for this, including potential transducers (PTs) which can divide the thousands of volts on an electrical transmission line down to a safe level. The output of a PT is then fed into the voltage signal conditioner, which further prepares it for digitizing.

Any signal conditioner used for high voltage measurement must be strongly isolated for the safety of the human operators of the equipment, and to avoid system damage or destruction.

It must be designed with the proper connectors. For temporary hook-up, safety/insulated banana jacks are common. For permanent hook-up, shielded screw terminals are common. Exposed contact connectors must be avoided.

A simple thermocouple sensor requires a high-quality signal conditioner in order to work. Although a T/C is passive, not requiring excitation or sensor supply, the tiny voltage potential that it generates at the connector side of the sensor must be isolated, amplified, and linearized. In addition, it needs a reference in order to provide an absolute temperature reading - otherwise, it can only produce a relative temperature reading, which is not very useful.

The amplification, isolation, and compensation aspects must be provided by the signal conditioner in hardware, while the linearization task can be done either in hardware or via software.

A tiny cold junction compensation (CJC) chip is provided here either inside the signal conditioner or within an annex box that connects to the conditioner. This CJC must be protected against ambient temperature swings caused by moving air or sunlight. They are typically installed within a special paste to keep their temperatures stable.

The science of making an accurate thermocouple signal conditioner cannot be overstated. Without serious attention to detail, accurate and linear thermocouple measurement cannot be made.

24-bit resolution is recommended with thermocouples. Why? A type K thermocouple sensor has a measuring range of -270° to +1260° C (-454° to 2300° F). That is a huge range.

Today, the mini blade thermocouple connector type has become the de facto standard, along with the color-coding that allows easy visual identification of the thermocouple type. Connecting a type K thermocouple into a signal conditioner that has been designed for Type S or T, for example, will result in wrong readings.

A “fixed type” thermocouple signal conditioner is one that has been made to be compatible with a specific thermocouple type, like Type J, K, or T, for example. Since Dewesoft offers high-performance universal signal conditioners for all of its DAQ systems, they have created DSI adapters for various sensors - including the most popular thermocouple types.

DSI-TH-x series adapters feature high accuracy cold junction reference measurement. 1 m thermocouple cable is included with a mini TC connector. Supported thermocouple types:

A good example of a universal type thermocouple signal conditioner is the KRYPTON isolated thermocouple modules from Dewesoft, available with 8 or 16 channels per module. These signal conditioners sample each channel at 100 S/s with a 24-bit resolution sigma-delta ADC per channel. Their input accuracy is typically ±0.02% of reading ±100 μV. They provide 1000V of isolation per channel, protecting the millivolt signals generated by thermocouples from interference.

Because the linearization can be performed very accurately and quickly by the included Dewesoft X data acquisition software, these modules are compatible with all major thermocouple types in use today: K, J, T, R, S, N, E, C, U, B.

White-color thermocouple connectors are used to indicate that the inputs are universal. The engineer simply selects the T/C TYPE that they are using on the channel setup screen within the Dewesoft X software, which then applies the correct linearization.

KRYPTON modules connect together via a single high-speed EtherCat interface, which carries power, data, and synchronization. They are made for harsh environments with high shock and vibration, water, dust, smoke, and from very low to high temperatures.

Although it also measures temperature, an RTD (resistance temperature detector) is a very different kind of temperature sensor compared with the thermocouple. The most important distinction is that RTDs are not passive sensors - they must be powered by the signal conditioner.

It supports both 3-wire and 4-wire RTD hookups. Note that 2-wire hook-ups are typically not recommended because the lead wire resistance gets added to the measurement resulting in artificially high-temperature readings, and there is no way to know exactly how much the measurement is wrong.

In a 3-wire hook-up, a third wire is used to detect the average lead wire resistance. The signal conditioner or accompanying software can then remove this offset in real-time, resulting in a much more accurate reading.

If we measure the resistance between R1 and R2 and subtract the resistance between R2 and R3, we will get the resistance of only the measuring end of the circuit at R(b). Of course, this assumes that the resistances are all the same. We can improve the accuracy even more by adding a fourth wire, as shown below:

You might notice that this hook-up is a full bridge. Lines 1 and 4 provide power to the circuit, and wires 2 and 3 are used to read back the lead wire resistance back to the RTD signal conditioner. In this way, we can completely offset variations in lead wire resistance.

So, if 4-wire hook-ups are always better than 3-wire, why do engineers sometimes opt for 3-wire? Usually, the answer lies in economics. If the RTDs are located a large distance from the measuring system, using three wires instead of four will save a lot of money in terms of cable cost and wiring cost. This can add up to a lot of time and money in large scale testing systems.

Accelerometer sensors that have a tiny amplifier built into them are also known as ICP® (a tradename of PCB Piezotronics) or more generically as IEPE, which stands for integrated electronics, piezo-electric. The output of these accelerometers is a relatively high-level voltage which can be sent back to the signal conditioner on good quality cable, at less expense than the cable required by charge type accelerometers.

But unlike charge type accelerometers that are passive and require no power, IEPE sensors need a voltage supply from the signal conditioner. This is normally presented in a form of a constant current of 4 to 20 mA and at a compliance voltage of 25 volts (typically).

Since IEPE accelerometers are made for measuring AC waveforms, this DC supply can be placed on the signal lines without creating any offset or measurement error.

Thus, the fundamental requirement of any IEPE signal conditioner is that it is able to provide this constant current power. The SIRIUS ACC provides a user-selectable constant current of 2, 4, 8, 12, 16 or 20mA at a 25 V compliance voltage.

Another useful feature, as provided on Dewesoft SIRIUS ACC modules, is a visual indicator that the sensor is connected and operating. SIRIUS DAQ modules do this by means of a green LED around the input connector bezel that lights up when the sensor is connected and working.

IEPE sensors nearly always employ a BNC connector, therefore it is important that the signal conditioner do the same. Referring to the picture above you can see the BNC input connectors on the SIRIUS ACC slice.

TEDS support is highly useful with IEPE sensors. TEDS (Transducer Electronic Data Sheet) is an IEEE 1451 standard based on storing information about the sensor inside the sensor itself, including its unit of measure, scaling factor, calibration information, and more.

The SIRIUS ACC signal conditioner can read this information when the sensor is connected, and automatically set up the sensor within the software. Dewesoft X software maintains a database of sensors that the user has connected, which can be managed by the user. TEDS is a huge time saver when many sensors must be connected in a short time, and also prevents set-up errors due to manual entry faults.

Input coupling is another important feature that the SIRIUS ACC conditioner provides. You can select from among DC (off), and two AC settings: 0.1 Hz and 1 Hz. Thus you can roll off low-frequency components close to the AC/DC threshold.

The frequency response of the signal conditioner. It does us no good to have a sensor that can measure up to 50 kHz when our signal conditioner cannot. So a bandwidth high enough to represent the top frequency signals of interest is clearly important.

SIRIUS ACC conditioners sample up to 200 kS/s/channel, providing an alias-free bandwidth of 70 kHz maximum. For higher speed applications, SIRIUS HS series signal conditioners provide sampling up to 1 MHz/s/ch using 16-bit SAR ADCs, with 100 kHz 5th order anti-aliasing filters.

One important aspect of measuring from virtually any sensor, but especially among dynamic ones like accelerometers is the dynamic range. This defines the maximum distance between the smallest and largest signals which can be measured. Each channel amplifier has two ADC"s that always measure the high and low gain of the input signal.

This results in the full possible measuring range of the sensor and prevents the signal from being clipped. With DualCoreADC® technology SIRIUS achieves more than 130 dB signal to noise ratio and more than 160 dB in dynamic range. See the video below.

24-bit ADCs provide an amazing resolution on the vertical axis. In addition, powerful anti-aliasing filtering on every channel adjusts to the selected sampling rate, preventing false signals caused by undersampling from destroying your measurements.

But the raw bit-count is just the beginning of the SIRIUS resolution story. For example, each input in a SIRIUS module literally has TWO 24-bit ADCs. One is set to a very high range, and one is set to a lower range.

The signal conditioner automatically uses the best amplitude signal from the dual-stream and creates a single stream of data with the best possible resolution. So to say that the SIRIUS has a 24-bit resolution is an understatement, since the result of this DualCoreADC innovation is amplitude axis resolution that is approximately 20 times better than systems with a single 24-bit ADC, with 20 times less noise.

Charge accelerometers require a signal conditioner that can read in their high impedance stream of charged ions (measured in pC, or pico coulombs), and convert them into a high-level voltage. They are based on the same piezoelectric principle as IEPE sensors (see above), but they have no built-in preamplifier. Therefore they do not require sensor power.

However, their high impedance output does not transmit as easily as the amplified output of IEPE sensors. Expensive low noise cables must be used and kept to as short a length as possible in order to prevent noise from influencing the signal. Still, charge accelerometers are still in use because they provide the highest possible temperature operating range, up to 538° C (1000° F), and the highest possible bandwidth. Specialty sensors are available with even greater operating temperature spans, low and high.

The SIRIUS CHG type signal conditioners are a great example of a versatile charge mode signal conditioner. In addition to handling charge sensors, it can also act as a low voltage conditioner and an IEPE signal conditioner.

There are three connectors commonly used by charge sensors: BNC, TNC, and 10-32. The SIRIUS CHG module is available with either BNC or TNC (essentially a threaded version of a BNC).

This is another important feature that the SIRIUS CHG conditioner provides. You can select from among 0.01 Hz, 0.03 Hz, 0.1 Hz, 0.5 Hz, 1 Hz, 10 Hz, or 100 Hz. Thus you can roll off low-frequency components close to the AC/DC threshold. This is important if you plan to integrate or double integrate the signal because noise and offset will be multiplied dramatically by this process.

The frequency response of the signal conditioner. It does us no good to have a sensor that can measure up to 50 kHz when our signal conditioner cannot. So a bandwidth high enough to represent the top frequency signals of interest is clearly important. SIRIUS CHG conditioners sample up to 200 kS/s/channel, providing an alias-free bandwidth in excess of 80 kHz at that top rate.

One important aspect of measuring from virtually any sensor, but especially among dynamic ones like accelerometers is the dynamic range. This defines the maximum distance between the smallest and largest signals which can be measured.

Each channel amplifier has two ADC"s that always measure the high and low gain of the input signal. This results in the full possible measuring range of the sensor and prevents the signal from being clipped. With DualCoreADC® technology SIRIUS achieves more than 130 dB signal to noise ratio and more than 160 dB in dynamic range.

24-bit ADCs provide an amazing resolution on the vertical axis. In addition, powerful anti-aliasing filtering on every channel adjusts to the selected sampling rate, preventing false signals caused by undersampling from destroying your measurements.

But the raw bit-count is just the beginning of the resolution story on SIRIUS DAQ systems. For example, each input in a SIRIUS module literally has TWO 24-bit ADCs: one is set to a very high range, and one is set to a lower range. The signal conditioner automatically uses the best amplitude signal from the dual-stream and creates a single stream of data with the best possible resolution.

So to say that the SIRIUS has a 24-bit resolution is an understatement, since the result of this DualCoreADC innovation is amplitude axis resolution that is approximately 20 times better than data acquisition systems with a single 24-bit ADC, with 20 times less noise.

Strain gage signal conditioners have perhaps the most complex job in the world of data acquisition. First, they must support multiple hook-up schemes, from the relatively simple full-bridge configuration to quarter and half-bridge configurations, and each with several wiring options. And when something other than a full bridge hook-up is selected, they are expected to also provide the resistors that are needed to complete the Wheatstone bridge circuit.

Of course, it must be possible to adjust the gain (aka sensitivity) of the signal conditioner. And to adjust how much voltage is sent to the strain gage sensor to power it (the excitation voltage). Filtering is almost always required with strain gauges, and this must be provided either in hardware or software, with selectable orders(filter strength).

That would seem like enough, but there are more requirements yet, including the ability to connect to one or more sense lines and use them to offset lead wire resistance changes caused by cable length and/or self-heating. Also, every strain gage has a Gage Factor - a number around 2, which must be entered and used by the system to convert the raw mV/V return from the sensor to a microstrain reading.

As a general statement, it should be an option for the engineer to choose to use the gage factor or not or to scale the return from the sensor in any way that they choose. For example, strain gage conditioners are also used for load cells, in which case we might want to see the reading in weight - kg or lbs. Every option should be provided to the engineer.

LVDT (linear variable differential transformer) transducers are used to measure linear displacement/position over relatively short distances. They consist of a tube that contains a rod. The base of the tube is mounted to a fixed position, and the end of the rod is affixed to something that moves.

As the rod is pulled out from the tube or slides back in, the sensor outputs a signal that represents the position of the rod from its starting point to its maximum deflection. The rod does not touch the inside of the tube, making it virtually frictionless, and the LVDT itself contains no electronics, making it popular in harsh environments.

An LVDT signal conditioner must provide the AC excitation that the transducer requires for operation. This AC drives the primary coil, which induces an output from each of the secondary windings, which are located toward either end of the tube. The signal conditioner must be able to take in and scale the differential output signal appropriately for display and measurement.

A good example is the SIRIUS STG with the DSI LVDT adapter from Dewesoft. Since the STG module has almost everything needed to perform as an ideal LVDT signal conditioner. All we add is a small adapter called the DSI-LVDT to the input connector of the STG module in order to complete the signal conditioner for use with LVDTs.

The DSI-LVDT has a TEDS chip inside it. When plugged into the SIRIUS-STG, the signal conditioner reads the information from the chip and automatically sets itself up as an LVDT signal conditioner. The engineer can further perform zero balancings and EU input and scaling if they want to. The DSI-LVDT generates the 4 to 10 kHz excitation that the sensor requires, and allows phase adjustment via a small potentiometer.

For large scale LVDT signal conditioning, the Dewesoft DS-16xLVDTr uses a unique ratiometric architecture to eliminate several of the disadvantages associated with traditional approaches to LVDT interfacing. The DS-16xLVDTr combines 16 channels of DSI-LVDT adapters in a 1U 19” rack-compatible housing.

The main advantage of the new design is the asynchronous excitation signal provided from an external function generator to a BNC front connector (IN connector). When using multiple DS-LVDTr devices the EXC signal can be daisy-chained from the BNC OUT connector to the BNC IN connector on the other device.

There are 16 DSUB-9M male connectors on the front panel for the connection to the Dewesoft data acquisition system. Each connector includes a trimmer for phase adjustment. On the rear panel are 16 DSUB-9F (female) connectors for the LVDT sensor connection. DS-16xLVDTr supports measurements with full-bridge and half-bridge LVDT sensor types.

A string pot or string potentiometer is a sensor that measures distance. It is configured as housing that contains a reel of rugged string that is spring-loaded so that it automatically winds back into the housing when the string is released.

The housing is mounted in a fixed position, while the end of the string is attached to something that will move, such as door, or a bracket or other object that will move back and forth with respect to where the housing is mounted. A good example is a movement between the “truck” of train wheels and the body of the train, which rides above it on a suspension system.

While a string pot is similar in operation to an LVDT, it is different in how it works. While an LVDT uses a differential AC potential to measure the position of a sliding rod, a string pot uses variable resistance to measure how much string has been deployed.

And from a mechanical point of view, the LVDT’s rod must move along a plane parallel with its tubular housing, while the string pot’s string is free to move in a wide arc from its point of emergence from the housing.

In order to condition a string pot’s output, we need a signal conditioner that can provide the excitation needed to invoke a resistance change from the sensor, and then read in the output. It is also necessary to be able to scale the reading into a useful unit of measurement, such as mm, cm, m, inches, feet, etc.

A good example is the SIRIUS STG module from Dewesoft. As a strain gage module, it is in the business already of providing excitation and reading in tiny voltage potentials. It can make resistance measurements in a basic half-bridge configuration. No additional adapter is needed in order to directly connect a string pot to the Dewesoft STG signal conditioner.

Digital inputs run the gamut from recording the simple on-off signals to handling a highly precise quadrature encoder, or gear tooth sensor that allows you to measure RPM, and other variants. They are referred to as digital because their signal is in the form of either high or low, unlike analog signals that have a waveform with many values between the highest and lowest ones which must be measured.

The simplest of digital inputs is the on/off type of signal that looks like a square wave if you look at it. These are sometimes referred to as discrete channels or event channels. Since they have only two states, they are often used to show the state of a door is open or closed, or a circuit being on or off, and a thousand other yes/no possibilities that we might need to measure.

Discrete inputs are normally output from a relay or transducer at TTL (transistor to transistor logic) levels, which are based on a 5V pull-up. In theory, the perfect TTL on/off signal would be 0V representing OFF (meaning a digital value of 0), and 5V representing ON (meaning the digital value of 1). However in practice, it is nearly impossible to achieve such precision, so the acceptable ranges have become 0 to 0.8V for OFF and 2V to 5V for ON.

These digital inputs are easily handled by Dewesoft’s SuperCounter® digital inputs, available on virtually every Dewesoft model DAQ system. These counter inputs have three lines (A, B, Z) which can handle encoders and RPM sensors - or you can use them as three separate discrete digital inputs (IN0, IN1, IN2). It is important to note that Dewesoft’s digital lines are sampled far above the sample rate selected by the user for their analog inputs, but are precisely aligned on the time axis with the analog inputs.

In addition, for large numbers of plain digital inputs, the Dewesoft IOLITE offers a 32 channel digital input module. This model 32xDI with easy screw terminal hookup and sensor power supply is ideal for high channel count data acquisition and control applications.

Dewesoft SuperCounter inputs can measure RPM and angle output values of rotating machines from a wide variety of RPM sensors, speed sensors, and encoders. Compared to standard counters, which only output integer numbers one sample later (e.g. 1, 1, 2, 2, 3, 4), SuperCounters can extract highly precise values like 1.37, 1.87, 2.37 between the analog samples, and fully synchronize them with the analog channels.

All of these can be connected to the Dewesoft SuperCounter and configured easily within the software. The outputs are perfectly synchronized with the analog data also being measured, allowing for advanced applications such as rotational and torsional vibration, combustion analysis, order tracking analysis, balancing, human body vibration, etc. to be performed.

Dewesoft X software has a built-in library of typical sensors, but it also has a flexible database that the engineer can use to create new sensors, name them, and call them up anytime in the future.

It is estimated that there are around one billion personal computers around the world, and with every single desktop computer, there is also a monitor attached to it. Every day, hundreds of computer monitors break down, and if you have a LCD monitor that you bought fairly recently and have questioned why it won"t turn on anymore, it"s most likely a power problem that can be fixed to save you hundreds of dollars. This guide will specialize on the computer monitor model LG L196WTQ-BF, but most monitors will follow similar design and can generally be fixed using the same instructions.

The main purposes of a Heating, Ventilation and Air-Conditioning (HVAC) system are to help maintain good indoor air quality (IAQ) through adequate ventilation with filtration and provide thermal comfort. HVAC systems are among the largest energy consumers in schools. The choice and design of the HVAC system can also affect many other high performance goals, including water consumption (water cooled air conditioning equipment) and acoustics.

The following actions detail how engineers can design a quality system that is cost-competitive with traditional ventilation designs, while successfully providing an appropriate quantity and quality of outdoor air, lower energy costs and easier maintenance.

The national consensus standard for outside air ventilation is ASHRAE Standard 62.1-2010, Ventilation for Acceptable Indoor Air Quality and its published Addenda. This standard is often incorporated into state and local building codes and specifies the amounts of outside air that must be provided by natural or mechanical ventilation systems to various areas of the school, including classrooms, gymnasiums, kitchens and other special use areas.

Many state codes also specify minimum energy efficiency requirements, ventilation controls, pipe and duct insulation and sealing and system sizing, among other factors. In addition, some states and localities have established ventilation and/or other IAQ related requirements that must also be followed.

Design in accordance with ASHRAE standards Design systems to provide outdoor air ventilation in accord with ASHRAE Standard 62.1-2007 and thermal comfort in accord with ASHRAE Standard 55–1992 (with 1995 Addenda) Thermal Environmental Conditions for Human Occupancy.

In some parts of the country, where temperature and humidity levels permit, natural ventilation through operable windows can be an effective and energy-efficient way to supplement HVAC systems to provide outside air ventilation, cooling and thermal comfort when conditions permit (e.g., temperature, humidity, outdoor air pollution levels, precipitation). Windows that open and close can enhance occupants" sense of well-being and feeling of control over their environment. They can also provide supplemental exhaust ventilation during renovation activities that may introduce pollutants into the space.

However, sealed buildings with appropriately designed and operated HVAC systems can often provide better IAQ than a building with operable windows. Uncontrolled ventilation with outdoor air can allow outdoor air contaminants to bypass filters, potentially disrupt the balance of the mechanical ventilation equipment and permit the introduction of excess moisture if access is not controlled.

Strategies using natural ventilation include wind driven cross-ventilation and stack ventilation that employs the difference in air densities to provide air movement across a space. Both types of natural ventilation require careful engineering to ensure convective flows. The proper sizing and placement of openings is critical and the flow of air from entry to exit must not be obstructed (e.g., by closed perimeter rooms).

Designers should consider the use of natural ventilation and operable windows to supplement mechanical ventilation.Consider outdoor sources of pollutants (including building exhausts and vehicle traffic) and noise when determining if and where to provide operable windows.

In most parts of the country, climatic conditions require that outdoor air must be heated and cooled to provide acceptable thermal comfort for building occupants, requiring the addition of HVAC systems. The selection of equipment for heating, cooling and ventilating the school building is a complex design decision that must balance a great many factors, including:

Where feasible, use central HVAC air handling units (AHUs) that serve multiple rooms in lieu of unit ventilators or individual heat pumps. Although there are many different types of air handling units, for general IAQ implications in schools, air handling units can be divided into two groups: unit ventilators and individual heat pump units that serve a single room without ducts; and central air handling units that serve several rooms via duct work.

Unit ventilators and heat pumps have the advantage of reduced floor space requirements and they do not recirculate air between rooms. However, it is more difficult to assure proper maintenance of multiple units over time and they present additional opportunities for moisture problems through the wall penetration and from drain pan and discharge problems. Central air handling units have a number of advantages as compared to unit ventilators and heat pumps serving individual rooms, including:

Easy access doors - All access doors are hinged and use quick release latches that do not require tools to open. Easy access to filters, drain pans and cooling coils is imperative.

Tightly sealed cabinet - Small yet continuous air leaks in and out of the AHU cabinet can affect IAQ and energy. The greatest pressure differentials driving leaks occur at the AHU.

Minimum 2 inch thick filter slots - For better protection of the indoor environment, as well as the equipment and ducts, the filters slots should be able to accommodate 2 in. or thicker filters.

Extended surface area filter bank - To reduce the frequency of filter maintenance and the cost of fan energy, the bank is designed to allow more filter area, such as the deep V approach or bags.

Air filter monitor - A differential pressure gauge to indicate the static pressure drop across the filter bank. This feature could easily be installed as an option in the field.

Corrosion resistant dampers and links - All moving parts such as pivot pins, damper actuators and linkages are able to withstand weather and moisture-induced corrosion for the full life of the system.

Indoor air can be two to five times more polluted than outdoor air; therefore, most HVAC system designers understand that increased amounts of outdoor air supply is generally better for IAQ. Yet there are concerns over the implications that this added amount of outdoor air supply has on the first cost and operating cost of the HVAC system, as well as moisture control for the school (too wet or too dry).

As a result, school designers often try to reduce the amount of outdoor air equal to — or even below — 15 cubic feet per minute (cfm) of outside air per person, the minimum for school classrooms, as established by the American Society of Heating, Refrigerating and Air -conditioning Engineers (ASHRAE) ASHRAE. In many parts of the country these concerns can easily be addressed by application of basic engineering principles and off-the-shelf HVAC equipment.

First cost, energy costs and moisture control do not have to be at odds with good IAQ. Energy recovery ventilation equipment can make the negative implications of 15 cfm per person of outdoor air behave like 5 cfm, while retaining the IAQ advantage of 15 cfm. This approach has been proven in many schools in various regions east of the Rockies, where advanced HVAC systems cost roughly the same as conventional systems, yet provide significant operating cost savings and IAQ advantages.

Proper location of outdoor air intakes can minimize the blockage of airflow and intake of contaminated air. The bottom of air intakes should be at least 8 inches above horizontal surfaces (generally the ground or the roof) to prevent blockage from leaves or snow. In northern locations, more separation may be needed due to greater snow depths or drifting snow.

Intakes should not be placed within 25 feet of any potential sources of air contaminants, including sewer vents, exhaust air from the school, loading docks, bus loading areas, garbage receptacles, boiler or generator exhausts and mist from cooling towers. If the source is large or contains strong contaminants, or if there is a dominant wind direction in the area, the minimum separation distance may need to be increased. Air admittance valves, an inexpensive and code-approved one-way air valve, can be added to sewer vents to eliminate the potential for release of gases into the surrounding air.

Grilles protecting air intakes should be bird- and rodent-proofed to prevent perching, roosting and nesting. Waste from birds and other pests (e.g., rats) can disrupt proper operation of the HVAC system, promote microbial growth and cause human disease. The use of outdoor air intake grilles with vertical louvers, as opposed to horizontal louvers, will reduce the potential for roosting.

Consider adding a section of sloped intake plenum that causes moisture to flow to the outside or to a drain if intake grilles are not designed to completely eliminate the intake of rain or snow.

In spaces where the number of occupants is highly variable such as gyms, auditoriums and multipurpose spaces, demand controlled ventilation (DCV) systems can be used to vary the quantity of outside air ventilation in these spaces in response to the number of occupants. One technique for doing this is to install carbon dioxide (CO2) sensors that measure concentrations and vary the volume of outside air accordingly.

If an auditorium fills up for school assembly, then CO2 concentrations will increase, a signal will be provided to the HVAC system and outside air volumes will be increased accordingly. When the spaces served by an air handler have highly variable occupancy, this type of control can both save energy and help control moisture (and mold) by reducing the quantity of humid outside air when it is not needed for ventilation. CO2 and other sensors must be periodically calibrated and maintained.

In addition to "atmospheric dust," airborne particulates can include pollen, mold (fungal) spores, animal dander, insect proteins, pesticides, lead and infectious bacteria and viruses. Designers can integrate features into the ventilation system that will provide benefits for the school occupants as well as the efficiency and longevity of the HVAC system. In addition, these features can reduce the need for expensive cleaning of the duct work and air handling units.

Air filters should have a dust-spot rating between 35% and 80% or a Minimum Efficiency Rating Value (MERV) of between 8 and 13. The higher the rating, the better the protection for the equipment and the occupants. It has been estimated that a 30% increase in static pressure across a coil results in a $200 per 10,000 cfm of air movement (at 7 cents per KWH). This does not include the added cost of cleaning dirty heating or cooling oils, drain pans, or air ducts. Designers should consider specifying a low efficiency (~10%) pre-filter upstream of the main filters. The pre-filters are generally easy and inexpensive to change and will capture a significant amount of the particulate mass in the air thereby extending the useful life of the more expensive main filters.

Design more filter surface area into ventilation systems. This has two advantages: the number of filter changes each year is reduced, thereby reducing the cost of labor to properly maintain the filters; and static pressure loss is lower, which saves money by reducing the amount of power needed to operate fans and blowers. Since different filter media are approximately proportional in their efficiency/pressure drop ratio, the most effective method for reducing pressure drop is to design more filter surface area into the filter system. This can be done by the specification of a filter with larger amounts of surface area, such as a pleated filter or bag filter. The next method is to increase the number and/or size of the filters in the airstream, for example, by mounting the filter slots in a "V" pattern, rather than a filter rack that is simply flat and perpendicular to the airstream.

Consider installing a simple pressure differential gauge across all filter banks. This will prevent school facilities personnel from having to guess whether the filter is ready for replacement. A gauge with a range of zero to 1.0 in. w.g. can save money and the environment by preventing premature disposal of filters that still have useful life and can prevent health and maintenance problems caused by overloaded filters that have blown out. The gauge should be easily visible from a standing position in an easily accessed location near the air handling unit.

The most effective means of reducing exposure of occupants to gases and VOCs is to manage and control potential pollution sources. Filters are available to remove gases and volatile organic contaminants from ventilation air; however, because of cost and maintenance requirements, these systems are not generally used in normal occupancy buildings or schools. In specially designed HVAC systems, permanganate oxidizers and activated charcoal may be used for gaseous removal filters.

Some manufacturers offer "partial bypass" carbon filters and carbon impregnated filters to reduce volatile organics in the ventilation air of office environments. Gaseous filters must be regularly maintained (replaced or regenerated) in order for the system to continue to operate effectively.

Although a typical HVAC system has many controls, the control of outdoor air quantity that enters the building can have a significant impact on IAQ, yet typically is not part of standard practice. Demand controlled ventilation is addressed as a method of humidity control, but is not otherwise discussed here because its primary use is to reduce the supply of outdoor air below the recommended minimum for the purposes of saving energy, not for improving IAQ.

Supplying acceptable quantit