Stanford Research Systems SR844, User Manual

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vi Specifications
SR844 RF Lock-In Amplifier
Reference
Relative Phase Error,
Orthogonality < 2.5 °
Phase Noise 0.005
°
rms at 100 MHz, 100 ms time constant.
Phase Drift
< 10 MHz < 0.1 ° / ° C
< 100 MHz < 0.25 ° / ° C
< 200 MHz < 0.5 ° / ° C
Demodulator
Zero Stability Digital displays have no zero drift.
Analog outputs have < 5ppm/
°
C drift for all dynamic reserve settings.
Filtering
Time
Constants 100
µ
s to 30 ks with 6, 12, 18 or 24 dB/octave roll-off.
None 10 to 20
µ
s update rate (X and Y outputs), 60
µ
s (R and
θ
outputs).
Harmonic Rejection
Odd Harmonics
-
10 dBc @ 3
×
Ref,
-
14 dBc @ 5
×
Ref, etc.
Other Harmonics and
Sub-harmonics <
-
40 dBc
Spurious Responses
-
10 dBc @ Ref
±
2
×
IF
-
23 dBc @ Ref
±
4
×
IF
<
-
30 dBc otherwise.
Displays
Channel 1 Channel 2 Reference
Type 4½ digit LED 4½ digit LED 4½ digit LED
Displayed X Y Reference Frequency
Quantities R [Volts] θ [degrees] Reference Phase
R [dBm] Y-noise [Volts] Aux Output Voltages
X-noise Y-noise [dBm] Offsets in % of Full Scale
AUX IN 1 AUX IN 2 IF Frequency
Elapsed Settling Time
Ratio The signal may be ratioed with respect to AUX IN 1 or
2. The ratio is applied to both X and Y before
computation of R, R[dBm], X-noise, Y-noise [V, dBm]
and so affects all of these quantities. The ratio input is
normalized to 1 V and has a dynamic range > 100.
Expand The CH1 and CH2 displays and outputs may be
expanded by
×
10 or
×
100.