Installation
2-2
2.2
Card configuration
2.2.1 Preamplifier module
Figure 2-1 shows the configuration of the preamplifier
module. Key items include:
❶
INPUT Terminals
The HI and LO INPUT terminals are pure copper studs
and nuts intended for connecting input signals to the
Model 1801. To minimize thermal EMFs, use only pure
copper lugs or wires for connections, and be sure that both
the terminals and connecting lugs are clean and free of
oxidation. See paragraph 2.4.4 for details on input
connections.
CAUTION
The maximum signal between
INPUTS HI and LO is 1V @ 100mA
peak (inputs over 2mV require one-
minute recovery). The maximum volt-
age between LO and chassis ground is
41V peak. Exceeding these limits may
result in damage.
❷
Offset Adjustments
V ZERO and I ZERO are externally accessible
adjustments for nulling voltage and current offsets
respectively. These controls need not be adjusted during
normal operation.
NOTE
Improper offset adjustments will
degrade performance. The offset adjust-
ments should only be performed using
the procedures covered in Section 5.
❸
Power Supply Connector
This connector attaches the preamplifier module to the
power supply card using the supplied cable. See para-
graph 2.4.1 for details.
1801 NANOVOLT PREAMP
INPUTS
HI
LO
41V
PEAK
V ZERO
I ZERO
CAUTION:
NO INTERNAL OPERATOR SERVICEABLE PARTS,
SERVICE BY QUALIFIED PERSONNEL ONLY.
!
KEITHLEY
2mV
PEAK
Input
Terminals
Zero
Adjustments
Power Supply
Connector
2
3
1
Figure 2-1
Preamplifier module configuration