Electromagnetically compensated weighing machine - has calibration system and compensation coil lever extension with receiver for calibration weight

摘要

The electromagnetically compensated weighing machine with built-in calibration consists of a load pan (10) which operates parallel load beams (12) (14) connected by a central vertical link (16). This link moves a horizontal, pivoted lever (18) which carries at one end a coil (26) moving in a permanent magnet pole-piece (28). Compensation current for the coil is controlled by a capacitive pick-up (30) on the horizontal arm. The compensation current is proportional to the weight on the pan and is used to drive a display (34). The other end of the horizontal arm is fitted with a V-shaped cradle (38) into which may be lowered a calibrated weight (40) operating a spring-loaded cam (54) when it is required to check the calibration accuracy of the machine.