DM502

Tektronix DM502
basic 3½ digit digital multimeter Tektronix DM502 Produced from 1975 to 1988 Manuals Tektronix DM502 Manual Tektronix DM502A Manual (OCR) (All manuals in PDF format unless noted otherwise)

Manuals – Specifications – Links – Pictures

The Tektronix DM502 is a basic 3½ digit digital multimeter plug-in for the TM500 system.

It has an Int/Ext switch that allows alternate input connections via the rear interface to be selected.

The DM502 is available with an input for temperature measurement with a transistor temperature probe (P6430) using an NPN transistor, e.g. a 2N2484 (any NPN-Transistor with h_FE >150 can be used).

The DM502A model adds an input for a PT-100 temperature probe (P6601), a True RMS converter, and offset circuits to read dB directly in all ranges. An "Option 2" instrument deletes the temperature measurement function, P6601 temperature probe, and all internal circuits associated with this function. The rear interface of DM502A is limited compared to the DM502: No current input and no reading output, see gallery below.

The 2 kΩ measurement range (+HI in DM502A) can be used for diode testing, since a current source of 1 mA is active and the reading corresponds to the (forward) voltage drop of the diode in Volts. The voltage can rise to a maximum of 10 V. A second voltmeter is needed to measure the voltage if 2 V are exceeded.

Key Specifications

Voltage ranges	200 mV to 200 V in decade steps; 1 kV (DC) / 500 V (AC) top range
Input impedance DM502	10 MΩ or direct JFET input >2 GΩ (by internal jumper)
Input impedance DM502A	10 MΩ
Current ranges	200 μA to 2 A in decade steps
Resistance ranges	200 Ω to 20 MΩ in decade steps