FAQs on Class 1 Calibration Weights Errors

摘要

Your weight is erroneous, even though it's just been calibrated. Even though it's class 1 and within tolerance, it isn't perfect. Class 1 weights have errors just like all other weights, and those errors are easily measured on an analytical balance. The following table shows the nominal value and both the high and low limits of class 1 weights: Nominal Value g Maximum ASTM 1 Minimum ASTM class 1 10,000 10,000.02500 9,999.97500 5000 5,000.01250 4,999.98750 2000 2,000.00500 1,999.99500 1000 1,000.00250 999.99750 500 500.00125 499.99875 200 200.00050 199.99950 100 100.00025 99.99975 For example, the 100 gram weight can be as much as 100.00025 gram and as low as 99.99975 gram and still be within ASTM class 1 (formerly class S) tolerance. A standard analytical balance reads out to four decimal places. If we round the maximum and minimum to four decimal places, then the maximum reading is 100.0003, and the minimum is 99.9998. So any reading in this range is possible on a "perfect" analytical balance. Of course, if the instrument has any errors (they all do), then those are additional.