The Tektronix DM501A is a 4½ digit True RMS multimeter plug-in for the TM500 system.

Tektronix DM501A
4½ digit True RMS multimeter
Tektronix DM501A

Produced from 1980 to 1984

Manuals
(All manuals in PDF format unless noted otherwise)

It replaced the DM501 (which suffered from accuracy limitations) in 1980. It also has a temperature input, requiring the P6601 PT-100 probe with a 2-pin LEMO S-series connector.

The DM501A was designed by Bill Mark.

Key Specifications

DC Voltage 200 mVDC to 1000 VDC in decade ranges; 0.05% + 0.01% (200 mV: 0.015% / 1000 V: 0.02%) FS
DC Input characteristics Input resistance 10 MΩ; CMRR >100 dB at DC, 80 dB at 50 and 60 Hz (1 kΩ unbal.), NMRR 60 dB at 50 or 60 Hz
AC Voltage 200 mVDC to 500 VAC in decade ranges; 0.6% + 0.05% (500 V: 0.2%) FS; True RMS;
AC Input characteristics Input impedance 10 MΩ // ≤160 pF; CMRR 60 dB at 50 or 60 Hz (1 kΩ unbal.)
DC Current 200 μA to 2 A in decade ranges; 0.2% + 0.015% FS
AC Current 200 μA to 2 A in decade ranges; 0.6% + 0.05% FS (20 Hz-10 kHz sine >5% FS)
Ohms 200 Ω to 20 MΩ in decade range; current 1 mA, 1 mA, 100 μA – 0.1 μA respectively; 0.15% (20 MΩ: 0.5%) + 0.015% FS
Temperature –62°C to +240°C (+0/-6°C or +2/-8°C any probe, uncal.); +150°C, ±2°C cal. probe, ±4°C uncal. probe; +150°C to +240°C, +0/-6°C or +2/-8°C any probe, uncal.

Links

Documents Referencing DM501A

Document Class Title Authors Year Links
Tekscope 1979 V11 N3.pdf Article A New DMM Family for the TM 500 Series Bill Mark 1979
070-2088-04.pdf Book TM500 Series Rear Interface Data Book 1985

Rear interface

The DM501A has a rear input, selectable by a front-panel button, on B28 (Hi) / A29 (Lo). Unlike the DM501 (non-A), it has no digital outputs. Input voltage on the rear interface is limited to 200 V peak / 100 V RMS.

Pictures

Components

Some Parts Used in the DM501A

Part Part Number(s) Class Description Used in
AD536 156-1259-00 Monolithic integrated circuit RMS/DC converter DM501A DM502A DM5010 Keithley 177 Keithley 179 Keithley 195A
Siliconix LD120 156-1306-00 Monolithic integrated circuit 4½ digit integrating ADC (analog section) DM501A DM5010
Siliconix LD121A 156-1305-00 Monolithic integrated circuit 4½ digit integrating ADC (digital section) 7A13 DM501A