AMC-400 Series Digital Transmitter with Smart Sensor 2
14
19. VREF Test Point:
This VREF Test Point is to be used by service technicians
only. It is the potentiostat sensor reference and must be 1.8
Volts DC.
20. Sensor:
This component may be a variety of 2 or 3 pin
electrochemical sensors. This component is permanently
fastened to the Smart Sensor 2 Module.
21. CTR Test Point:
This CTR Test Point is to be used by service technicians
only with appropriate instrumentation such as a voltmeter. It
is the potentiostat counter output used by a 3 pin
electrochemical sensor. Under ideal operation zero gas
situation it is normally 1.8 Volts DC VREF.
22. SIG Test Point:
This Sig Test Point is to be used by service technicians only
with appropriate instrumentation such as a voltmeter. It is
the potentiostat sensor output used. Under normal
operation zero gas situation it tracks the 1.8 Volts DC
VREF. When CO gas is applied this SIG Test Point
increases toward 3.6 Volts DC. When NO2 gas is applied
this SIG Test Point decreases towards 0 Volts DC.
3.5 SMART SENSOR 2 MODULE WITH CATALYTIC SENSOR
OVERVIEW
GND
VDD
VREF
SNS2
SNS3
SNS1
Smart Sensor 2 Module with Catalytic Sensor
16
20
SS2 male connector
Sensor Location
GND test point
VDD test point
VREF
SIG
Front
Back
REV
VER
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
SIG
SNS4
SNS5
SNS6
SNS7
TP3
TP1
TP2
TP4
19
test point
18
17
21
Figure 3-4 Smart Sensor 2 Module with Catalytic Sensor View
