Keithley 502B(Model502) free download

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INSTRUCTION MANUAL MODEL 502 MILLIOHMHETER Kelthley Instruments. Inc. 29776 Aurora Road/Cleveland, Ohio 44139/(216) 249-0400 INSTRUCTION MANUAL MODEL 502 MILLIOHMMETER OCOPYRIGRT 1975, ~ITRLEY INSTRUMENTS, INC. PRINTED JULY 1977, CLEVELAND, OHIO, U. S. A. CONTENTS SECTION .,,...*...,... IN'IRODUCTION I SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...*.. II OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III A. Connections (1) Low resistances (2) Higher resistances B. Procedure C. Battery Test D. Precaution5 CIRCUIT DESCRIPTION..,...,.,...,... IV ,...,... MAINTENANCE v A. Batteries B. Trouble Shooting C. Schematic, DR 12189 C D. Tube Voltage Diagram, DR 12256 C E. Replacement Parts List 0762 MODEL 502 MILLIOHMMlKTHH INl'FiODUCTION SECTION I - INTRODUCTION The Keithley Model 502 is a battery operated, portable milliohmmeter for measuring resistances from 0.00003 to 1000 ohms. The instrument employs an AC testing method, eliminating zero drift and permitting resistance readings in the presence of DC currents. The reading is presented on a linear scale panel meter. Typical applications of the instrument include measurement of con- tact resistance, conductivity of semi-conductor samples, fuse and squib testing, and electrolyte conductivity. Maximum power dissipation in the sample is 2 microwatts, permitting the measurement of detonator fuses without danger of detonation. In the measurement of contact resistance, the model 502 may be considered a "dry circuit" tester. However, the instrument may be used in the presence of DC biasing currents to measure the change in r