Field strength measuring appts. - has two or more electrodes with rotating screening electrodes for maintaining total exposed area constant

摘要

The field strength measurement appts. has at least two measurement electrodes (10a, 10b, 12a, 12b) screened w.r.t. measured field by a cylically rotated stop (26). Measurement devices connected to the electrodes measure the charge produced by the influence on the electrode as a measure of the field strength. The electrodes and stop are designed so that the sum of the exposed electrode surfaces remains constatn as the stop rotates. The measurement devices have two parallel high impedence measurement paths (34, 36) each between an electrode and the input of a summing amplifier (38). ADVANTAGE - Enables continuous field strength measurement and simultaneous field polarity determination with no adeverse interactions with a superimposed static measurement field.