How to Test a Weight Scale

The technical term for testing a weight scale is called calibrating.

Test your weight scale by using known weighted objects.Test your weight scale by using known weighted objects.
Every scale, at one point or another, whether due to factory regulation or government law, must be calibrated for accuracy. The only way a consumer can test a weight scale for accuracy is to place a known exact weight on the scale itself and read the results. Although you can test a weight scale by using any weight that you believe to be accurate, only certified calibration weights will give you a 100% true weight reading.

Place your scale on a flat and level surface. For ultimate accuracy, use a level to make sure the surface area is level.

Zero out your weight scale. Adjust your manual scale with its adjusting wheel or screws so it reads zero. A digital scale will need to be turned on, allowed to warm up for a few seconds, then adjusted with a knob to read zero.

Place a known weighted object onto the scale and read the results. For absolute accuracy, certified calibration weights must be used.

Read the weight that is registered on the scale. Adjust the scale, if needed, by turning a specifically labeled calibration knob or wheel to show the exact weight of the object you are testing. Digital scales may have an electronic calibration feature to calibrate the weight during a test by just a push of a button. Not all scales will have a calibration feature, just having a knob or wheel to zero the scale out when no weight is present. If you need to have absolutely exact weights for any object being weighed, a calibration feature is a must.

Repeat the testing procedure two more times, and after the initial adjustment, each weight that is registered should be exactly the same as the one previous. For ultimate accuracy, each test of the three must register the exact same weight.

Things You Will Need

  • Calibration weights or any known object with an exact weight
  • Level

About the Author

Dale Yalanovsky has been writing professionally since 1978. He has been published in "Woman's Day," "New Home Journal" and on many do-it-yourself websites. He specializes in do-it-yourself projects, household and auto maintenance and property management. Yalanovsky also writes a bimonthly column that provides home improvement advice.