Measuring and testing

The calorie counting antidote

These are great for shaking food items out of crackers, etc. This means that the level indicated will depend totally onthe programme content of the CD being played. They are used in a wide variety of temperature measurement and control instrumentation. Now you can have it - without spending a fortune. Until the advent of the HPIB, no standardized methods existed for interfacing instruments with computers.

The problems with calorie counting

Tell us if something is incorrect. Arrives by Tue, Sep Free pickup Tue, Sep Ships to San Leandro, Davis St. Frooshii Bramli Lunch Kit, 2-Pack. Its fresh seal Snap 'n Click technology locks in freshness and keeps your food fresh for a long time.

It helps measure out a serving and record the calories. Use it to shake all your salad ingredients and dressing together, or to make leftovers stay fresh and easy to find in your fridge.

It allows convenient on-the-go snacking that is convenient for work, outdoor activities and much more. With our wide range of product categories spanning grocery and household consumables, we offer you a variety of products for your family's needs. Our products are conveniently available online and in Walmart stores nationwide, allowing you to stock up and save money at the same time. To close, pinch seal at corner and slide thumb and finger along seal. For best results, press air out of bag before sealing.

Place bag on a microwave safe plate or dish. Open bag at least 1 inch to vent. Use short microwave duration of 2 minutes or less. Use defrost or medium to low power setting, do not use high power. Do not overheat food above F or bag may melt and break. Use caution when removing bag from microwave as contents and bag may be hot Bags are to be used for defrosting or reheating only.

Not for roasting, baking, boiling or cooking of any kind. Food Storage Bag Capacity Snack. Difficult to Get Food In or Out. I love snack size bags and have used them for years. I gave these a try because my Walmart now only sells these or the square ones. Considering the size of the opening, even small snacks are difficult to put IN without spilling. When you pull the zipper all the way open and wide as it could be, it is about the width of a golf ball.

This is terrible for mine and my daughter's lunches because part of the purpose of the snack bag in a lunch is for the kids to be able to put in their hand, remove a piece of food, and eat it without making a mess on the dirty lunch table or needing a dish or whatever to put it into. These are fine for small, granular snacks, but not a substitute for the old ones whose zipper was on the long side of the bag.

So disappointed our store doesn't sell the old ones anymore. Sfleet, July 11, While printing cup measurements is a great idea, the opening on the side of the bag is nothing but frustration.

The opening is only about 2 inches wide making it nearly impossible to get anything inside. Unless you're storing something long and thin like hot dogs or celery sticks, you need a funnel.

For protein-dense foods like meat, fish, eggs, dairy, or beans, use a palm sized serving. For veggies like broccoli, spinach, salad, carrots, etc. For carbohydrate-dense foods — like grains, starches, or fruits — use a cupped hand to determine your serving size.

Your own hand is a personalized and portable measuring device for your food intake. True, some people do have larger or smaller hands for their body size.

Still, our hand size correlates pretty closely with general body size, including muscle, bone — the whole package. Of course, just like any other form of nutrition planning — including calorie counting — this serves as a starting point.

So stay flexible and adjust your portions based on your hunger, fullness, and other important goals. This is a starting point. For more about this approach, click here: How to fix a broken diet: But should you tell them to eat 1 g of protein per pound of body weight? Or grams of protein with lunch? That makes gram-based recommendation pretty tricky. Fussing with numbers creates a lot of anxiety and confusion for clients. The simpler and clearer you can make your recommendations, the more likely clients are to follow them.

So, instead, why not share these guidelines? How much easier can healthy, individualized eating be? The most common cable fault is an open circuit, usually due toproblems close to or at the ends of the cables. A simple ohm metertest generally suffices. For multiplair cables where cable ends are many wires inside, a simplemultimeter is bothersome.

For those applications multi-pair cabletestes which find showrt circuits and broken wires are a good choise. In some application you need to measure the cable length. Dependingon the cable characteristics you know and the measuremenet instrumentsyou have, you can use a multimeter resistance measurement , RLC meter capacitance measurement.

General information Application notes and published papers from Riserbond - Very many cable fault locating documents. This method is sometimes impractical, however, because it cannot check for short circuits or you need to make very many test to measureresistance between very many wire combinations.

To solvel thos problem on multi-conductor cables, there are specialcable testing instuments designed for this.

Cable tester is fast and cheap - This simple microcontroller based cable tester verifies the correct wiring of the cable, up to 8 conductor cables. Rate this link Simple method tests cables - Engineers have long known how to test a cable for continuity by simply connecting all conductors in series and checking with an ohmmeter. This method is sometimes impractical, however, because it cannot check for short circuits.

This simple method solves the short-circuit detection problem. Connecting LED indicators at each shorting loop provides a visual indication. The unit consists of an audible signal monitor for "listening" to the signals present in an electronic device such as an audio system, receiver, amplifier, or tape deck at circuit points inside these devices. It also includes an RF detector probe and signal generator. You need special tools and proceduresto successfuly and safely measure high voltages.

This kind of devices are sold as ready made devices for example Tektronix, Agilent and Fluke sell those. Follow safety precautions when working around high voltages. Usually some form of equipment protection should be considered whenworking with high voltages.

Higher voltages not only cannot be indicated, but will also destroy the instrument. However, the range of any voltmeter can easily be extended using extra series resistance. Rate this link Electronic high voltage meters - Common voltmeters, digital or analog, usually range to some hundred volts maximum.

Rate this link Frequency measurements Frequency counter is a necessary instrument to check that certain circuit operated at thr right frequency. Frequency counter is an useful tool when you need to tune oscillators, measure some input signal frequency and when youplay with radio devices.

Inexpensive frequency counters that will measure frequency well into the microwave range are available to the hobbyist today. A frequency counter is an excellent means of accurately determining the frequency of unknown signals, or to see if an oscillator or a multiplier stage in a receiver or transmitter is working.

However, one must watch out as what is really being measured and exactly what the counter is "seeing". General information Frequency Counter Measurement Techniques - Inexpensive frequency counters that will measure frequency well into the microwave range are available to the hobbyist today.

Rate this link Frequency counter circuits Fr? Rate this link Prescaler circuits Prescalers are circuit which are used to extend the meausrement range of other frequency measuring circuits.

If you have for example a frequency coutner which can count up 10 Mhz, then with suitable prescaler circuit you can extend the measurement range to higher frequencies. For example suitable 1: And prescaler with higher division factor will enable you to measure even higher frequencies. The input resistance varies from down to 30 Ohms, and the input capacitance, excluding the PCB, no more than 5pF. Frequency to voltage converters are not usually as accurate as real frequency counter circuits, but they are still useful in many applications.

Rate this link Idea for a car tachometer - A tachometer is simply a means of counting the engine revolutions of an automobile engine. In this suggested idea a NE timer is configured as a monostable or one shot. The timer receives trigger pulses from the distributor points. Integration of the variable duty cycle by the meter movement produces a visible indication of the automobiles engine speed.

Rate this link Pulse period to voltage converter - This circuit converts a square wave input signal into a voltage proportional to the time between edges period of the signal, not the frequency, the range is from uS to to 10mS, which produces a voltage from mV to 10 volts. A functional feature, retriggering, of a monostable, one-shot 74xx multivibrator can yield frequency discrimination.

This circuit is a frequency discriminator that determines the relation of input-pulse frequency to a reference frequency. It tells if the input frequency is above or below the reference frequency. Rate this link Time measurements Got the Time? Rate this link Time-tag impulses with zero-crossing circuit - A "constant-fraction discriminator" usually performs the time-tagging of impulsive events, which have a peaking time of the signal amplitude.

Rate this link Audio measurements Audio volume is the most commonly measured audio signal property. VU and dB meters both measure the audio power involved in recording and they both use logarithmic scales to report that power.

When measuring electrical signals the following is true: VU is short for "volume units" and it is a measure of average audio power. A VU meter responds relatively slowly and considers the sound volume over a period of time.

A dB meter responds very rapidly and considers the audio power at each instant. When measuring electrical signals decibel is the difference or ratio between two signal levels; used to describe the effect of system devices on signal strength.

A signal strength or power level; 0 dBm is defined as 1 mW milliWatt of power into a terminating load. When measuring audio signal power vibrations in air the following measurements are made: The decibel abbreviated dB is the unit used to measure the intensity of a sound.

On the decibel scale, the smallest audible sound near total silence is 0 dB. A sound 10 times more powerful is 10 dB. A sound times more powerful than near total silence is 20 dB. What does 0 dB mean? This level occurs when the measured intensity is equal to the reference level. In this case we have equation: Most typically harmonic distortion needs to be measured. Harmonic distortion describes a nonlinear property of systemswhere the output of the system has added energy at frequenciesthat are at integer multiples of the frequencies input to thesystem.

The traditional technique is to input a single frequency F into the system under test, then take the output, apply a filter thateliminates F, and measure everything that's left over. This is usually done with a twin-T, high-G notch filter centered on F. Nowadays computer techniques can be applied where a more detailed analysis can be made usually based on FFT methods where harmonic and non-harmonic componentscan be identified.

Measuring audio music voltages on an AC voltmeter will give meaninglessresults as the voltmeter measures the average, over a fairly longintegrating time. This means that the level indicated will depend totally onthe programme content of the CD being played. Most multimeters are designed for AC power line work and DC measurements, so perfomance up to Hz or little bit over it is enough. To make any meaningful measurement, you need to us a CD with single frequency tones, and, unless you know that the meter measures well at higher frequencies, keep to a low frequency, ideally 50Hz, but generally up to acouple of hundred Hz will be OK.

Some of the "RMS" digital units might be useful ifthe frequency response is extended and flat enough. The multimeters vary in performance, so it is worth to check their performance on this even some cheap ones can perform accpetably on audio frequencies if a very good absolute accuracy is not needed. It produces fantastic displays on three LED bars that can be individually adjusted for any particular frequency range.

Double-blind and ABX tests do not allow the listener to know which component they are listening to, and furthermore don't allow the test controller to know either. This guards against visual cues to the audience including body language. This feature is adequate to prevent clipping but does a poor job of reading the average volume, or loudness, level. A high-resolution, average- not peak- reading volume-unit meter produces an accurate reading of loudness. The design is unique in that it detects both stereo channels on a single peak-hold capacitor.

All the adjustments in the circuit simultaneously apply to both left and right stereo inputs. The output is suitable for driving a bar-graph display or for analog-to-digital conversion and display with a microprocessor.

The circuit operates as a dual positive-peak-detector circuit. If you do you will need a good signal tracer, a device capable of amplifing minute amounts of audio to a point where they can be "read out" on a pair of monitoring headphones. Such a gadget is shown in the accompanying schematic. These components may develop excessive signal attenuation and losses, or poor isolation between inputs and outputs. These components can be tested using a RF signal source, termination resistors, and the Frequency Selective Voltmeter.

Rate this link Power and field strength meters A field strength meter is perhaps the simplest piece of RF test equipment that can be built. Used for checking transmitters, antenna experimentation, and testing RF oscillators, field strength meters provide an indication of the presence of RF energy.

They are generally not frequency sensitive and are useful where indication of a change in level is more important than the actual strength of the signal indicated. The meter works by converting any RF signal present at the antenna to a DC voltage. This voltage drives a meter movement to give an indication of relative RF. Usually the meter includes a control to reduce its sensitivity where required. An RF field monitor - This is the oddest application of a neon glow lamp, that is used as a electromagnetic field detector.

In fact the trigger voltage of these lamps is a little bit lower in presence of a strong field. A UJT transistor and a transformer a common low power AC transformer are used to produce a high voltage of about Vac. This voltage is reduced by the trimmer to a value just below the trigger voltage of the lamp. In presence of a strong field the trigger voltage drops and the lamp lights.

Rate this link 2. Beloq 1 GHz this proe has very flat response. This is an useful tool for RF interference troubleshooting! For EMC investigations, you can also clip this meter on to coaxial cables, rotator cables and other wiring in your shack, to find out where the RF currents are flowing, and how big they are. Rate this link Designing RF Probes - An RF probe is used to directly measure the level of RF voltage present at a particular point and is one of the most useful test instrument in the hands of the home brewer.

It is normally used with a digital multi meter to indicate the voltage level as dc voltage which is equivalent to the RMS value of the RF voltage being measured. However, the level of RF voltage being measured provides useful information only when the probe has been designed for use with a specific multi meter.

The design of the RF probe is a function of the DC input resistance of the meter we intend to use with it. If a new meter with a different input resistance is used with the probe the reading will be inaccurate. Rate this link Field-Strength Meter - Simple circuit based on old issue of "73 Radio Electronics", changed a few components to get better sensitivity. Rate this link Field Strength Meter - This RF field strength meter use only few parts, a printed circuit board is not necessary; components can simply be soldered to one another.

Rate this link Field-Strength Meter I - This circuit is a electromagnetic field meter which can be used for meaturing of transmitters output power. Rate this link Field-Strength Meter II - This circuit is an electromagnetic field meter which can be used for meaturing of transmitters output power.

Rate this link Funky Fresh? This circuit uses the AD, a high-frequency true-power detector. Using only 3 electronic components, it may rank as one of the simplest and cheapest homebrew projects.

When used with a high-impedance DC Voltmeter, it can be used to measure RF voltage and power , trace RF signals in a new design, and troubleshoot malfunctioning RF circuits. The voltage shown will not be accurate, since this is a rectifier probe, but the measurements are good enough for you to be able to determine where the RF stops, or if a stage is not giving the gain you think it should.

The unit is cheap and fairly basic, but perfectly adequate for its intended purpose. However, the output is not a pure sine wave. The unit covers a frequency range of KHz to 12MHz over five ranges shown below. It may also be used for RF alignment of SW circuits from 25 to 49 metres. The output may be amplitude modulated by an internal Hz audio tone approx.

The output level is adjustable in two ranges up to a maximum of about 4V pk-pk. The unit is mains powered V AC. Rate this link Impedance measurements Couplers Couplers are passive devices used in cable systems to divide and combine radio frequency signals. Many RF systems use directional test points and non directional test points. Directional coupler separate inbound and outbound signals separately. A non-directional coupler allows the measuring technician to see both forward and reverse signals at the same time sum of them.

This situation allows only one test point to be used for forward and reverse, but there is potential possibility for measuring errors due to reflections from the bad cable or passive. Reflections can add or subtract to the actual levels. The non directional coupler is a device presenting a fairly high impedance to the circuit being measured, minimizing the loading effects.

Non-directional couplers are generally implemented as high impedance towards the line resistive attenuation taps wired to the line. They typically have quite high attenuation dB typical. Directional coupler is a transmission coupling device for separately sampling through a known coupling loss either the forward incident or the backward reflected wave in a transmission line. A directional coupler may be used to sample either a forward or backward wave in a transmission line.

A unidirectional coupler has available terminals or connections for sampling only one direction of transmission; a bidirectional coupler has available terminals for sampling both directions. Directional couplers are used in a wide variety of applications and can satisfy almost any requirement for sampling incident and reflected RF or microwave power conveniently and accurately with minimal disturbance to the transmission line. Some general applications for directional couplers include line monitoring, power measurements and load source isolators.

A directional coupler has at least three ports: The signal passes between line in and line out ports with loss referred to as the insertion loss. A small portion of the signal power applied to the line in port passes to the tap port.

A signal applied to the tap port is passed to the line in port less the tap attenuation value. The tap signals are isolated from the line out port to prevent reflections. A signal applied to the line out port passes to the line in port and is isolated from the tap port. Building a Non Directional bi directional Coupler - A non directional coupler sees forward and reflected power at the same time, from either direction.

A non directional coupler can be built from a common drop splitter or directional coupler. The tap output is attenuated by 30 dB. Rate this link Directional Coupler Those coupled lines are used to construct directional couplers. Generally, in design of directional couplers microstrip and stripline forms are used. There are many kinds of directional couplers in different forms. The best theoretical performance available from a directional coupler, using ideal transformers, is a function of the turns ratio, and the terminating impedances.

At VHF and UHF frequencies, wire gauge and core material can be chosen to closely approximate the response based on the solution of these equations. The software comes in ascii-text and an X Windows interface using Motif. Signals applied to the input port are sent to the test port and signals coming into the test port can only go to the output port. The circuit really emulates an isolator in that the actual signal energy is not passed from port to port and the signal levels must be fairly low.

The circuit is well suited for testing the SWR of a variety of devices connected to the test port. Rate this link RF spectrum analyzers A mong the many measurement tools sought by the amateur radio experimenter, the most desired - but generally considered the least accessible - is the radio-frequency spectrum analyzer. Spectrum Analyzer is intended for visual inspection of the spectrum of an investigated signal on the oscilloscope screen. The signal can be continuous or pulsed.

Now you can have it - without spending a fortune. A mong the many measurement tools sought by the amateur radio experimenter, the most desired - but generally considered the least accessible - is the radio-frequency spectrum analyzer or SA. This need not be. Simple and easily duplicated, this homebuilt analyzer is capable of useful measure-ments in the 50 kHz to 70 MHz region. Rate this link Look before you leap: Rate this link Microwave Spectrum Analyzer on a budget - A practical approach to microwave signal analysis for the home experimenter.

The need for standard values can be met by using one or the other. Attenuators with equal terminations have a minimum attenuation of 0 dB. Unequal terminations place a lower limit on the attenuation.

A two way matching network uses a Rate this link Radioacivity There are many defices to detect radio active radiation. Geiger counters are devices to detect and measure ionizing radiation, as emitted by radioactive sources.

The heart of a geiger counter is the Geiger-Mueller-Tube. This is a gas filled tube, to which a voltage of several V is applied. Normally, the gas insulates and no current is drawn. When a radiation particle or quantum passes the tube, it triggers a gas discharge, i. The resulting current impulse can be amplified and made visible or hearable "clicking".

Glas mantle tubes are only suitable for beta and gamma rays, as any alphas are absorbed in the glass. Window tubes have a window usually at one end , which is sealed with a very thin foil or mica. Alphas can penetrate this window, and thus be detected, as well as betas and gammas. There are also diode based radioactive dosage meters in use. Adding heat to a system causes its temperature to rise. While there is no maximum theoretically reachable temperature, there is a minimum temperature, known as absolute zero, at which all molecular motion stops.

Temperatures are commonly measured in the Kelvin or Celsius scales, with Fahrenheit still in common use in the Unites States. There are many ways to measure temperature elecronically. A thermocouple is a very commonly used sensor for measuring temperature. It consists of two dissimilar metals, joined together at one end, which produce a small unique voltage at a given temperature. This voltage is measured and interpreted by a thermocouple thermometer.

In practical applications the so called cold side of the junction is kept close to ambient temperature by bonding it to a temperature stable mass. The hot side of the junction is exposed to the temperature to be measured. Because thermocouples measure in wide temperature ranges and can be relatively rugged, they are very often used in industry. Thermocouple is a A temperature sensing device made by joining two dissimilar metals. This junction produces an electrical voltage in proportion to the difference in temperature between the hot junction sensing junction and the leadwire connection to the instrument cold junction.

In typical applications the the hot side is in the end of sensor wire and the cold juction in the temperature measurement device near the sensor connector. In many cheap meters this cold junction is just in the same temperature as the meter itself, and it's temperature is measured in other means to compensate the effect of changes in cold junction temperature. Thermocouple detectors have low impedance. Thermocouples are available in different combinations of metals or calibrations.

The four most common calibrations are J, K, T and E. Each calibration has a different temperature range and environment. Propably the most commonly used type is K-type thermocouple, which is a Ni-Cr-sensor very suiable for degress celsius temteperature measurements can be used from to celsius.

The accuracy of any circuit or system that uses a thermocouple to determine the temperature of a process is limited by the accuracy of the method used to perform cold-junction compensation. In a thermocouple measurement, two wires of dissimilar metal join together at the "hot," or measurement, junction. The isothermal termination of the thermocouple wires provides a second "cold," or reference, junction.

The potential across the thermocouple is proportional to the temperature difference between the two junctions. Thus, to determine the absolute temperature of the hot junction, you must also know the absolute temperature of the cold junction. Resistance Temperature Detector RTD is a sensor that uses the resistance temperature characteristic to measure temperature.

There are two basic types of RTDs: A resistive thermal device RTD can measure temperatures as high as ? C over a great distance and without expensive signal conditioning. The most popular RTD is a standardized platinum temperature sensor called the PT, which exhibits ohms resistance at 0? C and a linear temperature coefficient of 0. C characteristic appears almost linear over a narrow range. A PRTD's transfer function of resistance vs.

C, are approximated by the equation: Unlike thermocouples, which deliver voltages that represent the difference between two temperatures, the resistance of an RTD represents the absolute temperature of that resistance.

Measurement is typically accomplished by driving a current of 1mA to 2mA through the sensor and measuring the voltage drop across it. Also semiconductors can be used as termperature sensors because semiconductor PN junction characteristics change when temperature changes.

This change is well defined and this can be used in some temperature measurement applications. The temperature - versus - bulk resistance characteristics of semiconductor materials allow the manufacture of simple temperature sensors using standard silicon semiconductor fabrication equipment. The ordinary semiconductor diode may be used as a temperature sensor because a forward biased voltage across a silicon diode has a temperature coefficient of about 2. C and is reasonably linear. The forward basing can be done with for example around 1 mA current through the diode.

To improve the performance of the diode as a temperature sensor, two diode voltages can be measured with two different currents typically selected to be about 1: The transistor sensor is used in diode mode by connecting the base and collector together or sensor is wired between base and emitter.

Semiconductor temperature sensors are available from a number of manufacturers. There are no generic types. The semiconductor or IC for integrated circuit temperature sensor is an electronic device fabricated in a similar way to other modern electronic semiconductor components such as microprocessors.

C typical , low cost, good accuracy if calibrated but also poor interchangeability. In general, the semiconductor temperature sensor is best suited for embedded applications - that is, for use within equipment. This is because they tend to be electrically and mechanically more delicate than most other temperature sensor types. The "out of the box" or interchangeability accuracy of most semiconductor temperature sensors is not particularly good.

If individual sensors are calibrated, significantly better measurement accuracy is possible tyically a two point calibration or three point calibration is used. Due to the high sensitivity of some sensors, they can be very good in measuring small temperature changes as opposed to absolute measurement. Bimetallic thermometers are contact temperature sensors found in several forms if you know where to look, e. They typically consist of a strip of bi-metal that has some electrical contacts affixed to it.

The temperature changes cause the strip to bend, making or breaking the connection as needed. You will often find long bimetallic strips coiled into spirals. This is the typical layout of a backyard dial thermometer. By coiling a very long strip it becomes much more sensitive to small temperature changes. In some applications temperature sensing needs to be done without contact to the measured subject. Those measurements use infrared IR techniques. Radiation Thermometers Pyrometers, if you will are non-contact temperature sensors that measure temperature from the amount of thermal electromagnetic radiation received from a spot on the object of measurement.

There are two types of commonly used sensors for this kind of applicatons: Pyroelectric Infrared Detectors and Thermopile detectors. Pyroelectric Infrared Detectors PIR convert the changes in incoming infrared light to electric signals.

The pyroelectric detectors output is proportional to rate of change of incident radiation. This means that pyroelectric detectors can only be used to detect temperature changes. This kind of PIR sensors are used for example in movement detectors where they sense the moving hot object like human through special optics this optics makes the movement of hot object change the radiation that gets to sensor change sharply when object moves.

Pyroelectric detectors have very high impedance requiring an internal impedance converting buffer to make them useable. Thermopile detector output is proportional to incident radiation. A thermopile is a number of thermocouples connected in series. The so called cold side of the junction is kept close to ambient temperature by bonding it to a temperature stable mass.

The hot side of the junction is exposed to incident radiation. Some thermopile sensors have a built-in thermistor which provides measurement of the ambient temperature thus allowing the temperature of the target to be calculated.

A thermopile sensor generates a voltage, which is proportional to the incident infrared IR radiation power. Because every object emits IR radiation with a power, which is a strict function of its temperature, one can deduct the object? This method is called pyrometry. Thermopile-type infrared and thermal detectors are used in a number of applications, including infrared spectroscopy, radiometry, security systems, and many consumer products. Although they do not provide vision-quality images as in the case of quantum detectors, thermopiles are still attractive for many low-cost commercial and industrial applications, mainly because they do not need cooling for operation and the technologies are relativly simple.

Thermopile detectors have low impedance. In addition to those some applications use Thermal Infrared imaging camera. Thermal Infrared imaging camera is a camera that responds to the infrared signals instead of normal light. Thermal infrared imaging cameras are detector and precision optics platforms that give us a visual representation of infrared energy emitted by all objects.

Typical applications for this type of cameras are night vision,wildlife observation, search and rescue, victim location, wild fire recon, predictive maintenance in power transmission and machinery, carona detection, process control and printed Circuit Board evaluation. Depending the applications the IR radiation can be shown as normal grayscale video or through real time color infrared output.

The color conversion converts different radiation intensities to different colors for easy visual inspection of picture. With a well calibrated camera, those different colors on picture can be directly mapped to different temperatures. Thermal infrared imaging cameras are expensive devices bceause they need special imaging sensors that needs to be cooled down to make them operate correctly.

This is the Seebeck Effect, discovered by Thomas Seebeck in The effect is multiplied when there are a number of junctions in series in the circuit, with alternate junctions in close thermal contact with each other. Schematics, mounting instructions and step-by-step instructions included.

Rate this link ECEFast Technical Papers - A selection of temperature measurement information document platinum resistance temperature detectors, thermocouple fundamentals, noncontact thermometers and infrared systems. Also information on water characteristics measurement conductivity, exygen, pH. This technique is a very good way to detect the temperature of a person's eardrum.

Rate this link International Thermocouple Colour Codes: Rate this link Measuring temperatures on computer chips with speed and accuracy-a new approach using silicon sensors and off-chip processing - Silicon sensors are becoming increasingly important transducers in electronic systems.

As systems become more complex, more compact, and denser-and run faster and hotter-it becomes increasingly vital to monitor critical temperatures. Traditional sensor techniques, such as thermocouples, thermistors, and RTDs, are now being displaced by silicon sensors, with their ease of integration and use. Silicon sensors, on the other hand, are linear, accurate, low-cost, and can be integrated on the same IC as amplifiers and any other required processing functions. The actual sensing element in a silicon sensor is a simple P-N transistor junction.

C and this fact may be used to develop a temperature measuring system. Rate this link Omega Technial Reference Section - Lots of technical documents on temperature measurement sensors. Rate this link Pyroelectric detectors - Pyroelectric Infrared Detectors PIR convert the changes in incoming infrared light to electric signals. Rate this link Remote diodes yield accurate temperature measurements - All of today's PC designs require thermal management.

Heat generation is a problem for PC-system designers. To prevent failures, you must incorporate thermal-management features in your design.

You can control temperatures by, for example, lowering device voltages and reducing clock rates so that devices generate less heat, or by increasing airflow so that the system can better dissipate heat into its environment. Because die temperature is a critical parameter, some devices incorporate a means to allow you to measure it.

It is aimed at engineer, student, scientist, and technologist alike. Rate this link Temperatures. Rate this link Thermocouples Introduction - The Thermocouple is a thermoelectric temperature sensor which consists of two dissimilar metallic wires, e. These two wires are connected at two different junctions, one for temperature measurement and the other for reference. Rate this link Track multisite temperatures on your PC - This low-cost circuit allows you to track four remote temperatures with thermistor sensors through the parallel port on your PC.

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