Tolerance, TCR and Temperature

Should be "One Spec" When you specify very accurate precision resistors, the TCR Char. and temperature are vital factors that are always considered as part of the equation.

Resistance Tolerance

Expressed as plus or minus percent of the nominal value (ohms) required. All PRC's resistors are calibrated and tested within specified limits at +25 Degrees Celsius. unless otherwise noted.

TCR Characteristic

The temperature coefficient of resistance is the variation in resistance with respect to a change in temperature (ambient and/or self-generated). This change is expressed in PPM, percent (%) or in Ω/ Ohms per one degree C.

Temperature

Since heat and cold are directly related to the TCR Char. and the resistance tolerance, please state the surrounding operational conditions affecting the resistors.

Wattage Ratings

Full power ratings are based upon standard (1%) resistance tolerances - at 25 degrees C. or to 125 degrees C. (depending upon the resistor type). Derating is required for higher temperatures and closer tolerances - please refer to derating curves for each type resistor. Sometimes a larger part physically - or closer (to zero) TCR Char. will help, but heat is heat and must be carried off in some manner.

Greater Stability is Important

The quality to resist permanent change must be designed in from the start. It is very difficult to stabilize or condition a general-purpose resistor and be confident that it will meet a critical application. All stability specs at PRC are designed for precise requirements ... even if you specify (1%) resistance tolerances.

Here's an interesting PRC Fact:

One of the shunt values we tested was a ten milliohm, 10 watt part (PLV10AL 0.01Ω ±1%) that developed over 30 amperes under full load. But, because of its aluminum oxide rectangular case and special low TCR element, the resistance change (under load) was less than ±0.1% ... and there was virtually no measurable EMF. Now that is a breakthrough! We certainly where impressed with the results ... and we are confident that we can help you in a similar manner.

Design your own shunt

You can actually design, test and fine tune engineering samples so they perform like a precision instrument. Try a few of our shunts tomorrow, because many of the popular values are in our stock for immediate delivery. Better yet, if we don't have exactly what you need in stock, special engineering samples will be manufactured to your specs quickly ... and at no cost.

Free Samples

Resistors are always free for tests. If you are unsure whether or not our part is right for your particular application simply request a few samples to test and we will manufacturer them to fit your specs and them ship them to you, usually within 7-10 working days, at no cost to you. Don't worry, there is no committment to buy so you have nothing to lose., Go ahead & send us your specs and you will see just how well our high quality precision part will perform to your specs!. All our parts are manufactured at our plant in beautiful Largo, Florida so you can trust you have a 100% American crafted part made right here in the good old U.S.A.