Fluke Biomedical 945A - Manual (Page 20)

4. The fourth mounting utilizes the Victoreen Model 948-10 Rack Chassis Adapter to mount a 946A-200
UDR into an existing Victoreen analog meter rack chassis, such as those used for the Victoreen 842
series of analog ratemeter.
The UDR is simply inserted into the selected mounting enclosure and secured using the front panel pawl
fastener.
WARNING
Ensure all power is off prior to connecting the field wiring.
Electrical Interface
Electrical connections at the preamplifier are made via the mating “MS” style connector supplied with the
detector. It is not necessary to open the preamplifier enclosure to complete the interconnection to the
ratemeter. The desiccant bags inside the preamplifier enclosure should be checked for moisture
absorbtion prior to placing into service. Each bag contains a color indicator that indicates when it should
be replaced.
NOTE
The electrometer circuitry in the preamplifier is highly sensitive to moisture and
physical damage. Use extreme care when the preamplifier case is opened as the
high impedance electrometer circuitry is easily damaged. Do not leave the
preamplifier enclosure in the open position for any extended period of time.
Electrical interconnections at the Model 946A-200 Readout are performed using the mating connector kit,
VICTOREEN part number 946A-100-4 (supplied with the Readout), by using the connector Input/Output
assignments provided in Tables 3-1 through 3-6, and the drawings provided in Appendix B. Refer to
drawing 945A-3, showing complete channel loop wiring, including remote alarms (if used)
Connector pins should be soldered to customer furnished cable, using 60/40 tin/lead resin core solder
with a soldering iron of 50 watts or less to avoid connector damage.
Table 3-1. Rear Panel Connections
Connector Contact Function
P1 Relay, Remote Alarm
Acknowledge
P2 Detector Connector, VICO
Loop Communications,
Remote Alarm Output
P3 AC Power Input
P6 Analog Outputs (4 - 20 mA, 0 -
10V)
P7 RS232C Communications
3-2