2
Installation
Making the Back Panel Connections
Thermo Scientific
Surveyor PDA Plus Detector Hardware Manual
13
Connecting the Analog Outputs
Two analog signal cables (twin-axial computer cables) are provided in the installation kit to
connect the analog outputs from the PDA detector to other data collection devices.
The analog signal cables have three wires protruding from the ends of the shielded cable. Two
of these wires are electrically insulated and carry an analog signal to data collection devices.
Typically, the wire with the clear insulation is connected to the positive analog output, and the
wire with the black insulation is connected to the signal ground (sometimes referred to as the
negative signal). The third wire is not insulated and grounds the cable shielding. The cable
shielding reduces signal noise caused by radio frequency interference and is most effective if
the bare wire is grounded at just one end.
At the detector back panel there are three different analog voltage outputs per channel:
CHA – 10 mV, CHA – 100 mV, CHA – 1 V, CHB – 10 mV, CHB – 100 mV, CHB – 1 V;
and a single ground per channel: GND A and GND B.
The ends (1/4-in.) of the analog signal wires are stripped and soldered to allow electrical
contact and to prevent fraying.
To make each electrical connection
1. Insert the end of the wire into the appropriate terminal in the 8-pin terminal connector.
Hold the wire in place while you tighten the small terminal set screw firmly onto the wire.
2. Insert the terminal connector into the 8-pin analog connector numbered 9 through 16 at
the back of the instrument (see
Figure 11.
View of the analog outputs
IMPORTANT
Do
not
connect the detector ground terminals to any earth ground on
your data system computer. Doing so leads to an increased noise level and a
subsequent decrease in sensitivity.
1 2
34
5
678
9
0
1 2
34
5
678
9
0
8-pin analog connector
