SRS SIM970 Multi Channel Digital Voltmeter

The Stanford Research Systems SIM970 is a four-channel digital voltmeter module engineered for precision DC voltage measurement in the SIM900 modular instrument platform. Each isolated channel delivers 5½-digit resolution across three selectable full-scale ranges (±199.999 mV, ±1.99999 V, ±19.9999 V) with optional three-decade autoranging. The instrument achieves exceptional accuracy—±(0.0002 + 2 counts) over 24 hours at 23 ±1 °C—through continuous autocalibration that eliminates offset and scale drift on every reading. All four channels are galvanically isolated from ground and from each other, with isolated BNC connectors that accept coaxial cables to suppress common-mode noise. The bright LED front panel updates at 3 Hz; remote access via RS-232 or GPIB yields 7½-digit (24-bit) resolution for data logging. Input impedance is 10 MΩ ±1%, selectable to >3 GΩ on ranges 2–4. The module rejects 90 dB of power-line frequency interference and operates safely to ±60 V center-to-shield without exceeding specified measurement performance.