Detcon TP-624D - Manual (Page 5)

Model TP-624D
TP-624D Instruction Manual Rev. 0.4 Page 1 of 40
1. Introduction
1.1 Description
Detcon Model TP-624D hydrogen sulfide sensors are non-intrusive “Smart” sensors designed to detect and
monitor H
2
S in air. Ranges of detection are 0-20ppm, 0-50ppm, and 0-100ppm. The sensor features an LED
display of current reading, fault, and calibration status. The sensor is equipped with standard analog 4-20mA
and Modbus
TM
RTU outputs. A primary feature of the sensor is its method of automatic calibration, which
guides the user through each step via fully scripted instructions displayed on the LED display.
The microprocessor-supervised electronics are packaged as a plug-in replaceable Transmitter Module that is
housed in an explosion proof junction box. The Transmitter Module includes a four character alpha/numeric
LED used to display sensor readings, and the sensor’s menu driven features when the hand-held programming
magnet is used.
PGM 1
PGM 2
MODEL TP-624D HOUSTON, TEXAS
FLT 1 2 CAL
MicroSafe H2S Gas Sensor
ALM ALM
TM
Figure 1 Sensor Assembly Front View
Solid State H
2
S Sensor Technology
The sensor technology is a patented solid-state mixed metal oxide semiconductor.
The sensor consists of two thin films, a temperature sensitive heater film, and a
hydrogen sulfide sensitive sensor film.
Both films are deposited on a silicon
microchip by vacuum deposition. The heater film elevates the operating
temperature of the sensor film to a level where a good sensitivity and response to
hydrogen sulfide is achieved. The sensor film is a proprietary mixed metal oxide
that shows an extremely stable and dynamic response to hydrogen sulfide gas.
Range of sensitivity is from parts per billion to percent by volume. The rugged
sensor is capable of maintaining its operating characteristics for periods of up to 7-
10 years in most industrial environments and as such, is supported by a 10-year
conditional warranty.