Detcon PI-500 - Manual (Page 4)

3.0.2 Universal Microprocessor Control Transmitter Circuit
The control circuit is microprocessor based and is packaged as a universal plug-in f ield replaceable module, facilitating
easy replacement and minimum down time. The universality includes the ability to set it for any range concentration
and for any gas type. These gas and range settings must be consistent with the PID Sensor Head it is mated with.
Circuit functions include a basic sensor pre-amplif ier, on-board power supplies, microprocessor, back lit alpha numeric
display, fault and calibration status LED indicators, magnetic programming switches, and a linear 4-20 mA DC output.
3.0.3 Base Connector Board
The base connector board is mounted in the explosion proof enclosure and includes: the mating connector for the con-
trol circuit, reverse input and secondary transient suppression, input f ilter and lugless terminals for all f ield wiring.
3.0.4 Explosion Proof Enclosure
The transmitter electronics are packaged in a cast metal explosion proof enclosure. The enclosure is f itted with a thread-
ed cover that has a glass lens window. Magnetic program switches located behind the transmitter module face plate are
activated through the lens window via a hand-held magnetic programming tool allowing non-intrusive operator interface
with the sensor. Calibration can be accomplished without removing the cover or declassifying the area. Electrical classi-
f ication is Class I; Groups B, C, D; Division 1 (explosion proof).
PI-500 Toxic Gas Sensors PG.4
detcon inc.
Program Switch #2
FLT CAL
MicroSafe™ Gas Sensor
HOUSTON, TEXAS
PGM 2
PGM 1
MODEL PI-500
CONTRAST
Fault & Cal LEDs
Program Switch #1
Menu Driven Display
Plug-in Microprocessor Control Circuit
Display Contrast Adjust
0
PPM
VOC
UNIVERSAL
TRANSMITTER
WHT
BLK
YEL
BLU
mA
VDC Power In
4-20 mA Output
Sensor
Base Connector Board
PID Sensor Head
Transmitter Electronics
in Explosion-Proof housing