(626) 284-9901
[email protected]
Riedon.com
  • Home
  • Cross Reference
  • Technical Information
  • How To Buy
  • FAQs
  • Blog
  • Contact Us
(626) 284-9901 mobile menu link
  • Home
  • Cross Reference
  • Technical Information
  • How To Buy
  • FAQs
  • Contact Us
  • About Us
  • Custom Resistor
Thanks for visiting our website, you also may be interested in our e-commerce site, shunts.com where you may find DC current shunts in stock to purchase.

Understanding Resistors and Temperature

A resistor's Temperature Coefficient of Resistance (TCR) tells how much its value changes as its temperature changes. It is usually expressed in ppm/°C (parts per million per degree Centigrade) units. What does that really mean?

Let's use an example: Riedon's 50 ohm 100 Series precision resistor has a (standard) TCR of 20ppm/°C. That means its resistance will not change more than 0.000020 ohms (20.1,000,000) per ohm per degree Centigrade temperature change (within the rated temperature range of -55 to +145°C, measured from 25°C room temperature.)

Assume our resistor is in a product that heats up from room temperature to 50°C. To find our 50W resistor's (maximum) change caused by that 25°C rise, multiply 0.000020 times 50 (the resistor value) times 25 (the temperature change.) The resistor's value would change no more than 0.025 ohms. (0.000020 X 50 X 25 = 0.025W.)

The actual change may be much smaller, depending on the specific characteristics of that resistor. If you must guarantee a smaller resistance change in your application, Riedon can provide a nonstandard TCR as low as 1 ppm/°C.

Custom Resistors
Request Samples

Featured
Products



Download The Current Sense
& Circuit Protection
Brochure Here

Riedon
Brochure





Download Our Brochure

Technical
Calculator


Use this technical resource to learn about Ohm's Law, design RTDs, Voltage Dividers, Wheatstone Bridges and more.

Technical Calculator

Riedon
Guide to Resistors

[email protected]

Riedon
News

  • Bourns Acquires Riedon, Inc.
  • Press Release - Riedon Unveils Digital DC Current Sensors - Making Current Measurement Even Easier
  • Shunt Accuracy Questions
  • Riedon's DC Ammeter shunt cross to Murata Shunt
  • Purdue house runs entirely on DC power: efficient nano-grid can be powered by solar panels, batteries or local utilities



Copyright © 2023 Riedon

Follow Riedon on Twitter
Follow Riedon on YouTube
Follow Riedon on Facebook
Cross Reference |  Technical Information |   How To Buy |   Contact Us |   About Us |  Custom Designed Resistors |