Ametek Thermox WDG-V, User Manual

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2-2 | Thermox WDG-V / VC / VCM with Blow Back
Sensor
Basic Elements of the Sensor
The WDG-V series analyzer consists of the following basic systems:
• The Plumbing
All inlet and outlet tubing, O
2
cell housing, and the combustibles flow
block. Also includes the calibration gas inlet and aspirator assembly,
flow sensor, and the aspirator used to pull the sample into the sensor.
• The Measuring System
The oxygen cell, combustibles detector, methane detector, and flow
sensor.
• The Temperature System
The electrical cell heater (furnace), sensor case heaters, the type “K”
thermocouple (maintains cell operating temperature). The sensing
cell operates at a constant temperature. The circuit board in the sensor
electronic box switches power to the furnace from the AC mains con-
nected to the sensor. This board also provides cold junction compensa-
tion to the thermocouple circuit.
• The Blow Back System
The insulated rear enclosure with fin heater, thermostat, accumulator
and three-way valve.
The WDG-V is a complete standalone unit. No separate controller is re-
quired. All required I/O is contained within the WDG-V including:
• Qty (3) configurable 4-20 mA outputs
• Qty (2) system alarm relays (Service and Data Valid)
• Qty (3) configurable process alarm relays
• Qty (1) RS485, 2-wire, MODBUS RTU interface (57.6 Kbaud)
• Qty (1) Contact input (for remote auto calibration trigger)
• Valve controls for Remote Calibration Unit (RCU)
The WDG-V is configured, calibrated and monitored via the MODBUS
RTU interface. AMETEK provides two options for communicating with
the WDG-V:
• AMEVision Display User Interface
• WDG-V Configurator Software via PC (provided with each unit)
Since the interface is industry standard MODBUS, custom user software
can also be written. For this purpose, consult the factory for the MODBUS
register definitions.