Keithley 195A Digital Multimeter with 1950 AC Option

The Keithley 195A is a 5.5-digit digital multimeter delivering high-resolution electrical measurements across DC voltage, resistance, and - with the 1950 AC Option

AC voltage and DC current. Manual or fast autoranging (150ms per range change on DCV) enables rapid measurement cycles, while a standard GPIB interface integrates directly into automated test systems. The instrument achieves 200,000-count resolution on a LED display and stabilizes to rated accuracy within 1 hour of warmup.

Technical Specifications

Measurement Ranges & Accuracy

• DC Voltage: 20mV to 1000V full scale; ±(0.025% reading + 6–8 counts) depending on range


• AC Voltage (1950 Option): 200mV to 700V; ±(0.3% reading + 200 counts) at 45Hz–10kHz, True RMS response


• Resistance: 20Ω to 20MΩ across seven ranges; ±(0.022–0.050% reading + 5–25 counts); automatic 2- or 4-terminal configuration


• DC Current (1950 Option): 20µA to 2A; resolution from 100pA full scale


• AC Current (1950 Option): 1nA to 2A, True RMS Input Characteristics


• DC Voltage Input Impedance: >1 GΩ (10 MΩ on 20V and above ranges)


• AC Voltage Input Impedance: 2 MΩ shunted by <75 pF; bandwidth -3 dB at 250 kHz typical


• Maximum Input: 1000V peak (DC and AC); AC also limited to 107 V·Hz


• Crest Factor: Up to 3:1 allowable for AC measurements Environmental & Physical


• Operating: 0°C to 50°C, 0–80% RH (to 35°C)


• Storage: -25°C to 65°C


• Power: 105–125V or 210–250V selectable, 50–400 Hz, 24 VA maximum


• Dimensions: 127 mm H × 216 mm W × 359 mm D


• Weight: 3.2 kg

Key Features

• 5.5-digit LED display (200,000 counts)


• Fast autoranging with 150 ms per-range settling on DCV


• True RMS AC measurements with AC coupling


• Automatic 2- and 4-terminal resistance measurement


• Temperature coefficient: <±(0.1 × accuracy)/°C across 0–18°C and 28–50°C


• Reading rate: 3 readings/second (1 reading/second on 20 MΩ range)

Typical Applications

• Electronics assembly and component validation


• Laboratory bench testing and general electrical measurement


• Automated test system integration via GPIB

Compatibility & Integration Standard GPIB interface supports integration into ATE platforms. 90–110 V and 180–220 V power supply versions available on request.