Det-Tronics THZ HART Combustible Gas Transmitter - Manual

DESCRIPTION
The DEC-THZ Toxic Gas Transmitter is a Class I,
Division 1 approved device when used with an
approved sensor, and is compatible with the entire
line of Det-Tronics electrochemical toxic gas sensors.
It provides a linear 4-20 mA output proportional to the
sensor input, as well as a large digital display for indi-
cating the detected gas level.
The model DEC-THZ Toxic Gas Detector is com-
prised of two assemblies:
• A Det-Tronics Model C7064X electrochemical gas
sensor, which is a two-wire, loop-powered gas sen-
sor providing a linear 4-20 milliampere output.
• A Model THZ Transmitter, which is specially config-
ured to accept the 4-20 mA signal from the
C7064X gas detector. The Model THZ provides
the HART signal along with the analog signal.
TRANSMITTER COMMUNICATION
The DEC-THZ transmitter output is ready for direct
interface with HART or non-HART based DCSs, PLCs,
and other computer-based SCADA systems. The
DEC-THZ is easily configured, monitored, or calibrat-
ed from anywhere on the 4-20 mA loop using a stan-
dard hand-held HART Communicator (such as a
Model HC275), a HART-based control system, or an
Asset Management System (AMS).
AUTOMATIC DIAGNOSTICS
The transmitter performs continuous sensor diagnos-
tics. If the sensor fails or otherwise stops sending a
signal during operation, the transmitter warns of a
trouble condition, and provides a HART digital error
message that can be read by a HART communicator
or system. The transmitter uses a modular electronics
design, which allows for easy removal and replace-
ment in the event of a malfunction.
TRANSMITTER ENCLOSURE
The transmitter’s aluminum enclosure features a
sealed, dual-compartment interior to isolate and pro-
tect the electronics from humidity, moisture, or corro-
sive agents that could possibly enter through the
cable conduit entry. The enclosure also has a screw-
on front cover with glass window to enable easy view-
ing of the detected gas level, and a screw-on rear
enclosure cover to enable easy access to the wiring
termination area. The enclosure provides two 3/4 inch
NPT conduit entries — one for the sensor, and one for
field cabling.
INSTRUCTIONS
Toxic Gas Detector
with HART Output
DEC-THZ
© Detector Electronics Corporation 2002 12/02 95-8550
DET
-
TRONICS ®