TRIAL CONSTRUCTION OF AN AUTOMATIC CALIBRATION DEVICE FOR STANDARD WEIGHTS - DIRECT SUBMULTIPLE CALIBRATION OF TEST STANDARD WEIGHT SET

摘要

To establish a national mass standard, submultiple and multiple systems are employed to calibrate highly accurate sets of weights based on national prototype kilograms. However, calibration techniques require great skill and many years for the measurement of weights. To promote an efficient calibration process, an automatic calibration device with built-in standard weights is being developed. In the first step, a device was manufactured on an experimental basis; this device automatically calibrates a set of built-in ring-shaped standard weights (100 g ～ 1 kg) using the submultiple method. Then, preliminary experiments were performed. In the second step, a weight-exchange mechanism which directly calibrates test standard weights (1000, 500, 200, 200, 100 g) using the submultiple method was added to the device and calibrations were carried out. Results of preliminary measurements reveal a standard deviation of approximately 0.04 ～ 0.02 mg.