ViewSmart 200/2050/2150 Controller User's Manual
Document: UM-1021
Revision Level B
26
Figure 3.5
3.1.5
OPTIONAL ELECTROCHEMICAL SENSOR INPUT BOARD #10-0220
Important!
10-0220 PCB’s may only be installed into motherboard position P1.
The 10-bit 10-0220 Two Channel
Electrochemical Sensor Input
option shown in Figure
3.6 allows these popular gas sensors to be connected directly to the ViewSmart 200
without additional signal conditioning or transmitters. Each channel is equipped with a
preamplifier, bridge amplifier, sensor coefficient jumpers and a 2 position coarse gain
jumper for setting the gain of the bridge amplifier. Socketed resistors R4 and R16 control
the gain of the preamplifier and are installed at the factory (consult factory if sensor gas
type is to be changed after shipment). Fault supervision circuitry forces the ViewSmart
200 into a FAULT condition upon sensor failure or removal.
This option may also be configured to accept 4-20mA inputs for mixing an
electrochemical sensor and a current loop into the same board. Placing any channel’s 2
position TOXIC/4-20mA jumper into 4-20mA position and installing the associated
precision 100 ohm socketed resistor allows 4-20mA signals to be applied to its mA + /
mA - terminals. Bridge amplifiers are bypassed in this configuration.
