Reading Resistors for People who are Color Blind

Reading Resistors for People who are Color Blind

Resistor band chart

Reading Resistors

  • Through-hole resistors are designed to be read visually by looking at the color bands
  • Unfortunately, this is not an accessible design practice because this presents a significant challenge for people who have difficulty distinguishing certain colors
  • Below you’ll find some ways to help mitigate this

Option 1: Store resistors separately

  • When you first get the resistors, separate the common resistors (e.g. 10k, 330, 4.7k) into different envelopes
  • When you are disassemble your project, store the resistors back in the appropriate enveloples.

Option 2: Use App to Help Identify Colors

  • There are apps that help identify colors such as Color Blind Pal
  • These can be effective, but it will depend on the consistent lighting

Option 3: Use a Digital Multimeter (DMM)

  • The most consistent way to measure the resistance of resistors is with a digital multimeter
  • If you would like to use on borrow a DMM, please let me know and we will be happy to loan you one

Using a DMM to Read Resistance

1) Resistance should be measured outside the circuit 2) Always remove the resistor before measuring 3) Plug in probes (black goes to common, red goes the appropriate ports) 4) Turn knob to Resistance measurement

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5) Touch one probe to each end of the resistor 6) Adjust the knob until a valid reading appears

  • If meters reads OL, 1, or 0, then adjust the knob

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