Verify that the scale is level and stable. Load the scale a few times to align the internal parts. Place both poise bars on the zero indicators for each beam. The beam pointer should be centered on its indicator. If the beam pointer is not centered, adjust the balance screw to center the pointer.
Load the scale with weight(s) as directed below. When the reading stabilizes, the scale should indicate a weight that is within 1% of the test weights.
For adult/pediatric scales, place ten 10 lb (5 kg) calibration weights on the platform and note the indicated weight. Then add the other ten calibration weights and note the indicated weight.
For infant scales, place the 1 lb (0.5 kg) calibration weight on the platform and note the indicated weight. Replace the 1 lb (0.5 kg) weight with a 10 lb (5 kg) weight and note the indicated weight