Testing Resistors In My Lab

Resistors seem like a simple topic. Just Ohm’s Law:

R = I/E

and a digital volt meter that reads resistor values in Ohms.

But different resistors by size, value, tolerance, temperature compensation, age, and manufacture have a problem with noise. I present several resistor types all with the same value of 100kΩ. Each resistor is tested for stability over time and temperature.

Use this simple procedure to test your own resistors before use in projects that require low noise such as scientific instrument prototypes. I start with 4 minutes of resistance data logging at room temperature followed by an additional 3 minutes of resistance data logging at an elevated temperature using my pinched fingers around the body of the resistor.

Fluke 125B Resistance Data Log / PartIncrease Temperature during Resistance Data Log / Part Using Heat from Finger
Photos showing my lab test procedure for measuring resistor stability and noise: 4 minutes at room temperature ~75 °F and 3 minutes with heat applied to the body of the resistor from my pinched fingers ~94 °F.

Test results for 8 different 100KΩ resistors in my lab. Resistors 2), 7), and 8) appear to be the worst after heat applied.

Resistor InfoPhoto7 Minute Resistance Plot
1) 100kΩ 1% Metal Film 1/4 Watt. Purchased on Amazon:
1280 Pieces 64 Values Resistor Kit, 1% Assorted Resistors 1 Ohm-10M Ohm 1/4W Metal Film Resistors – Brand: Aniann
2) 100kΩ 1% Metal Film 1 Watt. Purchased on Amazon:
1000pcs 1W Resistor Kit, 1 Ohm – 1M Ohm 1 Watt Metal Film Resistor Assortment Kit with 1%. Brand: AUKENIEN
3) 100kΩ 1% Metal Film 1/4 Watt, 50ppm.
31 Values, 100 pcs per Value Resistor Kit. Purchased on Newark. Brand: Farnell
4) 100kΩ 1% Metal Film 1/4 Watt, from my parts bin.
5) 100kΩ 10% Carbon 1/2 Watt, from my parts bin.
6) 100kΩ 5% Carbon 1 Watt, from my parts bin.
7) 100kΩ 5% Carbon 1/4 Watt, from my parts bin.
8) 100kΩ 5% Carbon 1/2 Watt, from my parts bin.
Resistor stability test results for 8 different resistors in my lab.

In this last test I verify the stability of my resistance data logging test procedure. Use this information if you would like to repeat this test on your own resistors.

Baseline Resistance TestBaseline Resistance Test ResultsTest Voltage Used During Resistance TestsTest Voltage
Test setup for measuring resistor stability in this article.

References

This site is designed as an educational reference, serving as a reliable source for all information related to resistors.

Author: Ron Fredericks

Ron Fredericks is looking for research laboratories that need online go-to-market technical support. He holds 2 patents in biophysics, 2 awards from Wind River an Intel company for online publishing, and a specialist award from Adobe for reusable training content. As editor for two high tech magazines he has experience organizing technical market strategy and motivating individuals into content creation experts. Product integration from components to client solutions, interfacing instruments to computers, and building hardware/software prototypes are some examples where he thrives.

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