Detcon TP-624C - Manual (Page 3)

3.0 D ESCRIPTION
Detcon MicroSafe™ Model TP-624C, hydrogen sulf ide sensors are non-intrusive “Smart” sensors designed to detect
and monitor H2S in air. Ranges of detection are user-settable between 0-20 ppm, 0-50 ppm, and 0-100 ppm. One of
the primary features of the sensor is its method of automatic calibration which guides the user through each step
via instructions displayed on the backlit LCD. The sensor features f ield adjustable, fully programmable alarms,
relays for two gas level alarms, and one for any fault condition. The sensor is equipped with both an analog 4-20
mA, and serial RS-485 output. These outputs allow for greater f lexibility in system integration and installation. The
microprocessor supervised electronics are packaged as a plug-in module that mates to a standard connector board.
Both are housed in an explosion proof condulet that includes a glass lens window which allows for the display of
sensor readings as well as access to the sensor’s menu driven features via a hand-held programming magnet.
3.0.1 Sensor Technology
The sensor technology is a patented solid state metal oxide semiconductor. The sensor consists of two thin f ilms; a
temperature sensitive heater f ilm, and an hydrogen sulf ide sensitive sensor f ilm. Both f ilms are deposited on a sili-
con microchip by vacuum deposition. The heater f ilm elevates the operating temperature of the sensor f ilm to a
level where a good sensitivity and response to hydrogen sulf ide is achieved. The sensor f ilm is a proprietary metal
oxide that shows a dynamic response to hydrogen sulf ide gas. Range of sensitivity is from part per billion to % 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.
Detcon Model TP-624C Hydrogen Sulfide Sensor PG.3
Construction of
Semiconductor Sensor
Sensor
Film
Heater
Film
Silicon
Microchip