Avtron Model T477W Bonding Meter
with B14703 Battery Pack Replacement Instructions
Part Number T477WC15292
Circuit Description
Subject to the EAR, ECCN [9E610.a].
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15 C.F.R. Part 730 et. seq. Transfer, retransfer, or disclosure of this data by any means to a non-U.S. person (individual or company), whether in the United States or abroad, without any
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CIRCUIT DESCRIPTION
The T477W is designed to measure values of resistance from 2000 milliohms to less than 0.2 milliohms. Connections to the unknown
resistance are made by four wire (Kelvin) connections that consist of two current and two voltage sensing leads. The meter circuit
provides a regulated alternating current @ 78 Hz that is fed through the unknown resistance while the voltage generated across that
unknown resistance is sensed. Since the sensed voltage is caused by a constant current, and voltage is proportional to resistance, the
meter interprets voltages in terms of resistance.
