Signal Channel

Voltage inputs 
Singleended or differential 
Sensitivity 
2nV to 1 V 
Current input 
10^{6} or 10^{8} Volts/Amp 
Impedance 
Voltage: 10 MW + 25 pf, AC or DC coupled
Current: 1 kW to virtual ground 
Gain accuracy 
> ±0.2% 
Noise 
6 nV/ÖHz at 1 kHz (typical)
0.13 pA/ÖHz at 1 kHz (10^{6} V/A)
0.013 pA/ÖHz at 100 Hz (10^{8} V/A)

Line filters 
60 [50] Hz and 120 [100] Hz notch (Q=4 ) 
CMRR 
100 dB to 10 kHz, decreasing by 6 dB/OCT above 10 kHz 
Dynamic reserve 
>100 dB without prefilters (<5 ppm/°C) 
Reference Channel 
Frequency range 
0.001 Hz to 102 kHz 
Reference input 
TTL or sine (400 mVpp minimum) 
Input impedance 
1 MW, 25 pf 
Phase resolution 
0.01° front panel, 0.008° through computer interfaces. 
Absolute phase error 
<1° 
Relative phase error 
<0.001° 
Orthogonality 
90° ± 0.001° 
Phase noise 

Internal reference 
Synthesized, <0.0001°rms at 1 kHz. 
External reference 
0.005° rms at 1 kHz, 100 ms, 12 dB/oct. 
Phase drift 
<0.01°/°C below 10 kHz, <0.1°/°C below 100 kHz. 
Harmonic detection 
2F, 3F, ... nF to 102 kHz (n <19,999). 
Acquisition time 
2 cycles + 5 ms or 40 ms (largest applies) 
Demodulator

Stability 
Digital outputs and display: no drift. Analog outputs: <5 ppm/°C for all dynamic reserve settings. 
Harmonic rejection 
90 dB 
Time constants 
10 ms to 30 ks (6, 12, 18, 24 dB/oct rolloff). Synchronous filters available below 200 Hz 
Internal Oscillator 
Range 
1 mHz to 102 kHz 
Frequency accuracy 
25 ppm + 30 mHz 
Frequency resolution 
4 1/2 digits or 0.1 mHz, whichever greater 
Distortion 
80 dBc (f <10 kHz), 70 dBc(f >10 kHz) @ 1 Vrms amplitude 
Amplitude 
0.004 to 5 Vrms into 10 kW (2 mV resolution),
50 W output impedance, 50 mA maximum current into 50 W 
Amplitude accuracy 
1% 
Amplitude stability 
50 ppm/°C 
Outputs 
Sine, TTL 
Displays 
Channel 1 
4 1/2 digit LED display with 40 segment LED bar graph.
X, R, Xnoise, Aux 1 or Aux 2.
The display can also be any of these quantities divided by Aux 1 or Aux 2. 
Channel 2 (SR830) 
4 1/2 digit LED display with 40 segment LED bar graph. Y,
q, Ynoise, Aux 3 or Aux 4. The display can also be
any of these quantities divided by Aux 3 or Aux 4. 
Offset 
X, Y, R can be offset ±105% of full scale 
Expand 
X, Y, R can be expanded by 10 or 100 
Reference 
4 1/2 digit LED display 
Inputs and Outputs 
CH1 output 
±10 V output of X, R, X noise, Aux 1 or Aux 2. Updated at 512 Hz. 
CH2 output (SR830) 
±10 V output of Y, Y noise, Aux 3 or Aux 4. Updated at 512 Hz. 
X, Y outputs 
In phase and quadrature components (±10 V), updated at 256 kHz (rear panel) 
Aux. A/D inputs 
4 BNC inputs, 16 bit, ±10 V, 1 mV resolution, sampled at 512 Hz. 
Aux. D/A outputs 
4 BNC outputs, 16 bit, ±10 V, 1 mV resolution 
Sine Out 
Internal oscillator analog output 
TTL Out 
Internal oscillator TTL output 
Data Buffer 
8,000 points (SR810), 2 x 16,000 points (SR830) 
Data Storage Rate 
Up to 512 Hz 
Trigger In 
TTL signal synchronizes stored data recording 
Remote preamp 
Provides power to the optional SR550, SR552, and SR554 preamplifiers. 
General 
Interfaces 
GPIB and RS232 interfaces standard. All instrument functions can be controlled and read through GPIB or RS232 interfaces. 
Power 
40 Watts, 100/120/220/240 VAC, 50/60 Hz. 
Dimensions 
17"W x 5.25"H x 19.5"L 
Weight 
23 lbs. 