SRS SIM922A Diode temperature monitor

• Single-channel LED display
• 1.4 K to 475 K with Si, GaAs or GaAlAs diodes
• 1.4 K to 873 K with RTDs
• Two analog outputs:
• Linearized V proportional to T
• Sensor voltage (buffered)
• Remote interface

The SIM922A has a programmable, precision 10 µA current source to provide sensor excitation. Results can be displayed in either kelvins or volts.

The SIM922A employ four-wire measurement circuits (±I excitation leads, ±V sense leads), making readings insensitive to series lead resistance. Sensor excitations can be disabled to reduce power dissipation at sensitive cryogenic stages. Measurements are performed at five readings per second.

The scaled analog output (±10 V) produces a voltage proportional to measured temperature, with a full-scale range from 10 K to 1000 K. A relative-mode button subtracts the last absolute reading prior to scaling, to provide expanded resolution for temperature deviations. The second (monitor) output is the buffered, low-noise raw sensor voltage without any additional processing.

Either analog output may be coupled to the SIM960 Analog PID Controller for high-performance, closed-loop temperature control.

A factory-standard calibration curve is pre-programmed for each model. Non-volatile memory also permits storage of a 256-point custom calibration curve to convert sensor units (V or Ω) to temperature units (K).

Results are displayed on an easy-to-read, 4-digit LED display.

Full remote operation is available over the serial interface.