Atec Stanford-Research-SR810-SR830 User Manual
Digital lock-in amplifiers
phone: (408)744-9040
www.thinkSRS.com
Stanford Research Systems
· 1 mHz to 102.4 kHz frequency range
· >100 dB dynamic reserve
· 5 ppm/°C stability
· 0.01 degree phase resolution
· Time constants from 10 µs to 30 ks
(up to 24 dB/oct rolloff)
· Auto-gain, -phase, -reserve and -offset
· Synthesized reference source
· GPIB and RS-232 interfaces
· SR810 ... $3850
(U.S. list)
· SR830 ... $4750
(U.S. list)
The SR810 and SR830 DSP Lock-In Amplifiers provide high
performance at a reasonable cost. The SR830 simultaneously
displays the magnitude and phase of a signal, while the SR810
displays the 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 1 mHz to 102 kHz and 100 dB of drift-
free dynamic reserve.
Input Channel
The SR810 and SR830 have differential inputs with 6 nV/√Hz
input noise. The input impedance is 10 MΩ, and minimum
full-scale input voltage sensitivity is 2 nV. The inputs can
also be configured for current measurements with selectable
current gains of 10
6
and 10
8
V/A. A line filter (50 Hz or
60 Hz) and a 2× line filter (100 Hz or 120 Hz) are provided
to eliminate line related interference. However, unlike
conventional lock-in amplifiers, no tracking band-pass filter
is needed at the input. This filter is used by conventional lock-
ins to increase dynamic reserve. Unfortunately, band pass
filters also introduce noise, amplitude and phase error, and
drift. The DSP design of these lock-ins has such inherently
large dynamic reserve that no band pass filter is needed.
Extended Dynamic Reserve
The dynamic reserve of a lock-in amplifier, at a given full-
scale input voltage, is the ratio (in dB) of the largest interfering
SR810 & SR830 DSP Lock-In Amplifiers
Digital Lock-In Amplifiers
SR810 and SR830 — DSP lock-in amplifiers
SR830 DSP Lock-In Amplifier