2 modular mechanical design – Detcon FP-524D-HRT User Manual
Page 7
Model FP-524D-HRT
FP-524D-HRT Instruction Manual
Rev. 0.1
Page 3 of 48
1.2 Modular Mechanical Design
The Model FP-524D-HRT Sensor Assembly is completely modular and is made up of four parts:
1) FP-524D with HRT Bridge Plug-in Transmitter
2) Field Replaceable Combustible Gas Sensor
3) Connector PCB
4) Splash Guard.
FP-524D-HRT Plug-in Transmitter
The Plug-in Transmitter Module is a microprocessor-based package that plugs into the connector board located
in the explosion proof junction box. Circuit functions include extensive I/O circuit protection, sensor pre-
amplifier, sensor temperature control, on-board power supplies, microprocessor, LED display, magnetic
programming switches, and a linear 4-20mA DC output with HART. Magnetic program switches located on
either side of the LED Display are activated via a hand-held magnetic programming tool, thus allowing non-
intrusive operator interface with the Transmitter Module.
Calibration can be accomplished without
declassifying the area. Electrical classifications are Class I, Division 1, Groups B C D.
Figure 5 Circuit Functional Block Diagram
PGM
1
PGM
2
MODEL
FP-524D-HRT
HOUSTON, TEXAS
FLT
1
2
CAL
MicroSafe
LEL Gas Sensor
ALM ALM
TM
Figure 6 FP-524D-HRT Transmitter Module
Field Replaceable Sensor
The Detcon combustible gas sensor is a field proven, replaceable type sensor. It can be accessed and replaced
in the field by unthreading the lower half of the sensor housing. The cell can then be unplugged and replaced.
The Detcon combustible gas sensor has an infinite shelf life and is supported by a 2 year warranty.
I/O
Circuit
Protection
4-20mA
Display
Micro-
Processor
Temperature
Control
Pre-Amp
Analog 4-20mA Out
HART communication
Power In
Power Supply
Plug-In
Sensor
Element