Operating instructions

AMC-DTR Sensor Transmitter User Manual
15
4.10 “Sensor Type” and AMC-DTR Signal Conditioning
Catalytic bead and electrochemical sensors obviously have different signal conditioning
requirements. In addition, same sensor types have different response coefficients, signal
strength and gain and offset requirements. The block / wiring diagram in Figure 14 illustrates
how AMC-DTR’s are able to accept many sensor types without the need of manual
potentiometers or jumpers. Smart Sensors carry this setup information with each sensor.
I/O Power
Supply Board
TB1
Reference
Active
Sensor Excitation
Switching Power
Supply
“Sensor Volts”
Digital Pot
“Balance Adjust”
Digital Pot
Bridge
Amplifier
“Simple” Catalytic-
Bead LEL Sensor
Reference
Active
“Smart” Catalytic-
Bead LEL Sensor
Memory
Device
“Smart” Sensor
Serial Interface
+Vdd
Common
I/O Power
Supply Board
S1
3
6
4
7
1
8
Or
Analog Switch
(Display Assy)
Electrochemical
Sensor Amplifier
(Display Assy)
Analog / Digital
Converter
(Display Assy)
3-Wires
8-Wires
2
3
2
1
Display Assembly
TB2
Reference
Counter
“PreAmp Gain Adjust”
Digital Pots
uAmp / V
Amplifier
“Simple” Electro-
chemical Sensor
Memory
Device
“Smart” Sensor
Serial Interface
+Vdd
Common
Display Assembly
S1
3
6
4
7
1
8
Or
3-Wires
8-Wires
2
3
2
1
Sense
“Smart” Electro-
chemical Sensor
Reference
Counter
Sense
Catalyitc Bead
Bridge Amplifier
(I/O Power Supply)
Ribbon cable
between I/O
& Display Assy.
Figure 14: AMC-DTR Block / Wiring Diagram