Measuring resistance

Electrical resistance is measured by either of two methods: The constant current technique sources a known current through an unknown resistance and the resulting voltage is measured. This technique is generally used for resistance values below M ohms. Examples of just some of the Keithley products which use this technique are,and

Measuring resistance

DSP drives speed and accuracy; coherence saves the day - DSP techniques lead to faster, less costly frequency-response tests and enable the use of a powerful concept, the coherence function, which acts as a watchdog to help identify and quantify common but easy-to-miss measurement errors.

Best of all, this watchdog works for free. Smart signal conditioners compensate for the errors and extract the true signals from the dross. Pressure transducers, accelerometers, temperature sensors, and linear-position sensors are often imperfect devices, prone to nonlinearities and gain and offset errors.

Rate this link Tech Tips: Rate this link Using a multimeter - A meter is a measuring instrument. An ammeter measures current, a Measuring resistance measures the potential difference voltage between two points, and an ohmmeter measures resistance. A multimeter combines these functions, and possibly some additional ones as well, into a single instrument.

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It can be used to test cables, AC power levels and Batteries. You'll often find yourself out on the road with problems that are causing you grief, but you aren't quite sure why. Rate this link What is a decibel? The ratio may be power, or voltage or intensity or several other things. Measuring resistance this link Measuring instrument interfaces IEEE is propably the mostly adopted communication bus and protocol used in electronic measusing equioment.

Measuring resistance

Some others call it GPIB general-purpose instrumentation bus. Until the advent of the HPIB, no standardized methods existed for interfacing instruments with computers. IEEE remained for more than two decades the industry's primary standard for enabling instruments and computers to talk with one another.

IEEE standard did a good job of defining the communications hardware, it initially gave short shrift to interfacing's software aspects. More than a decade elapsed before the evolution of the necessary software standards, particularly SCPI standard commands for programmable instruments.

IEEE was not the only interface used. RS ports have became popular on slower instruments. The two top contenders for the instrument-interfacing standard of the future are Ethernet and USB.

You can find one or both in many instruments. Scopes that offer communication ports other than IEEE are becoming increasingly common. USB will also play a major role. The most obvious reasons for turning to computer-standard interfaces in place of IEEE for instruments are cost, size, cable length of instrument networks, and increasing difficulty of installing specialized peripheral controllers in newer PCs.

Don't be fooled by the new protocols' high nominal bit rates; instrument interfacing usually involves short messages.

Using an instrument as a Web server is a new aspect in interfacing. Rate this link Oscilloscopes Every scientist, engineer, and technician involved in any form of electronics has used an oscilloscope. Scope displays of amplitude as a function of time provide intuitive and easily interpreted pictures of signals.

Oscilloscope is one of the most important test instruments foravailable engineers. It is useful for very many electronics measurement. The main purpose of an oscilloscope is to display the level of a signal relative to changes in time.

You can use an oscilloscope to analyze signal waveform, get some idea of signal frequency and many other details. Scopes are ment for looking at the qualitative aspects of the signal like signal waveform, esitence of signal, etc.

For making quantitative measurements, a scope is "usually" a bad choice for example multimeter is more accurate tool to measure DC voltage levels than a scope.

It is quite typical for the scope to be out by a percent or two or three but if you're counting on that kind of accuracy, you're using the wrong tool.

Traditional oscilloscopes used a CRT screen and were completely analogue devices. Those analogue oscilloscopes are still very usable devicesnowadays.

Analogue oscilloscopes work very well as general testing instrumentfor viewing repetitive signals. Many simple and cheap analogue oscilloscopes have typical bandwidth of 20 MHz.

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Some better ones go to Mhz or higher in bandwidth.Four-terminal sensing (4T sensing), 4-wire sensing, or 4-point probes method is an electrical impedance measuring technique that uses separate pairs of current-carrying and voltage-sensing electrodes to make more accurate measurements than the simpler and more usual two-terminal (2T) sensing is used in some ohmmeters and impedance analyzers, and in wiring .

Measuring Slip Resistance. People generally slip on wet surfaces or wet shoes, not clean dry surfaces.. Consider specification of a wet Pendulum Test Value (PTV) of 36+ in final use conditions. Great multimeter with a variety of parameters you can measure.

It gives you the normal ac/dc voltage and amperage as well as resistance and continuity. Measuring resistances is similar to measuring voltages, with a key difference: You must first disconnect all voltage sources from the circuit whose resistance you want to measure.

That’s because the multimeter will inject a known voltage into the circuit so that it can measure the . Osmosis: Osmosis, the spontaneous passage or diffusion of water or other solvents through a semipermeable membrane (one that blocks the passage of dissolved substances—i.e., solutes).

The process, important in biology, was first thoroughly studied . SpecMetrix systems deliver unmatched measurement data of coating thickness and film thickness. Our systems measure wet or dry coating on any substrate.

Measuring Impedance