The SR810 Lock-In Amplifier and SR830 Lock-In Amplifier provide high performance at a reasonable cost. The SR830 simultaneously displays the magnitude and phase of a signal, while the SR810 displays magnitude only. Both instruments use digital signal processing (DSP) to replace the demodulators, output filters and amplifiers found in conventional lock-ins. The SR810 and SR830 provide uncompromised performance with an operating range of 1mHz to 102kHz and 100dB of drift-free dynamic reserve.
- 1mHz to 102.4kHz frequency range
- >100dB dynamic reserve
- 5ppm/°C stability
- Time constants from 10µs to 30ks (up to 24 dB/oct roll off)
- Auto-gain, -phase, -reserve and -offset
- Synthesised reference source
- GPIB and RS232 interfaces
The SR810 and SR830 Lock-In Amplifiers have differential inputs with 6 nV/√Hz input noise The input impedance is 10MΩ, and minimum full-scale input voltage sensitivity is 2nV. The input can also be configured for current measurements with selectable current gains of 106 and 108 V/A. A line filter (50Hz or 60Hz) and a 2x line filter (100Hz or 120Hz) are provided to eliminate line related interference. However, unlike conventional lock-in amplifiers, no tracking bandpass filter is needed at the input. This filter is used by conventional lock-ins to increase dynamic reserve. Unfortunately bandpass filters also introduce noise, amplitude and phase error, and drift. The DSP based design of these lock-ins has such inherently large dynamic reserve that no tracking bandpass filter is needed.