Signal Input Section - Stanford Research Systems SR124 Operation And Service Manual

2 – 12

2.3.1 Signal input section

2.3.1.1 Signal input
Near the center of the instrument, in the "CONTROL INHIBIT"
block, is a large locking toggle switch. When in the upper position,
none of the front-panel (or remote) interface functions are operable.
The analog signal processing of the SR124 remains fully functioning
while the Inhibit switch is up, but no controls will respond. For nor-
mal operation, the Inhibit switch should be left in the lower position.
Where applicable, the corresponding remote command is listed,
along with the page where it is defined, in parentheses, like this:
(FORM, 4 – 11 ).
The left-hand section of the instrument comprises the "Signal Input".
See Figure 2.3 for detail.
SENSITIVITY
OVLD
200
100 500
µV
50 1
2
20
10 5
5 10
knob
2 20
1
50
100
500
200 200
100
nV 500
SIGNAL INPUT
A
OVLD
A–B
6
I (10 ) AC Float
8
I (10 ) DC Ground
Input Couple Ground
A/I B
BNC
BNC
10 MΩ 10 MΩ
Figure 2.3: The SR124 front panel signal input section.
User input signals are applied to the SR124 through the "A I", or the
"A I" and "B" BNC connectors. The input configuration is controlled
Stanford Research Systems
mV
INPUT FILTER
10
20
5
50
2
knob
100
1
10% ENBW
Q-factor
Band Pass
High Pass
Low Pass
Notch
Flat
Type
SR124 Analog Lock-In Amplifier
Introduction
kHz
Hz
f trim
depth
Push to select
Hold to
null
knob
RESERVE
High Res.
Signal
Normal
Monitor
Low Noise
Reserve
BNC
600 Ω