ENMET TDX Series - Manual (Page 4)

ENMET Corporation TDX-Series
2
2.0 Operation 2.0 Operation
TDX-Series Unit can be of single or multi-channel configuration. Each unit monitors the gas concentration at a single
remote location and consists of a sensor, transmitter. The sensor/transmitter without local read out can be connected to
a controller module via 2-conductor shield cable. The transmitter converts the direct output signal of the sensor into a
standard 4-20mA DC signal. The sensor/transmitter is mounted at a strategic location to monitor the designated
hazardous gas in ambient air.
3.0 Description of Components 3.0 Description of Components
3.1 Description of Sensor
Sensor: The sensor consists of an electrochemical cell. As the designated gas passes through the cell
membrane, it reacts with the electrolyte to produce a small electrical current proportional to the
partial pressure of gas in the area.
3.2 Description of Transmitter
Cover Screws: These screws fasten the face cover to the transmitter unit. Face cover must be removed for
installation or for performing calibration adjustments.
Cable Entry: This fitting provides strain relief entry for cable from the controller module.
Zero Adjust screw: This screw is used to adjust the zero setting during calibration.
Span Adjust screw: This screw is used to adjust the sensitivity during calibration.
Terminal Strip: This terminal is used to connect the 24VDC power from a controller unit. (See installation for
proper wiring.)
Figure 1: Sensor/Transmitter Module Diagram
Cable Entry
Terminal
Strip
Sensor
PCB
TCX-Transmitter
Multimeter Range:
40 to 200 mV
40mV = 4mA
200mV = 20mA
Zero Adjust Screw
Span Adjust Screw
V+ (24VDC)
V– (24VDC)
V+
V–
(PT+)
(PT–)