Instruction and operating guideline CO-detector
Type:
VCD2 CO-Detector
2
Introduction
In many applications it may be more cost effective to replace a sensing head
with one precalibrated at a testing station or laboratory, so reducing disruption
of the measuring system. To enable this, some CiTiceLs are available as 4-20 mA
Transmitters, comprising a three electrode Toxic Gas CiTiceL and a circular
Surface Mount Design (SMD) printed circuit board (PCB). The prime features of
these units are ease of use, compactness, and the ability to replace both CiTiceL
and electronics very quickly.
The EasyCal PCB has an amplifier circuit to convert the microamp level output
signal of the sensor to the industry standard 4-20 mA output for two-wire,
remote monitoring systems. The circuit employed imposes no constraints on the
sensor, so the performance characteristics of the sensor are unaltered by the
addition of the circuit board. The microprocessor board removes the need for
potentiometers used on the standard boards, and only requires a single button
press when gas is applied for calibration. This makes the calibration process
quick and simple to perform.
All transmitters are fitted with a diffusion mounting assembly (the Mounting
Nose) for convenient mounting and fast replacement in a wide range of
weatherproof housings. It requires a 25 mm diameter hole in the outside wall of
the housing to allow installation, and also features a
calibration plug for easy zeroing and exposure to
calibration gas. A bonded membrane and mesh is
included to prevent the ingress of dirt and dust
particles into the sensor.
Besides periodic recalibration, transmitters are
maintenance-free, and should give faultless service
throughout the working life of the sensor. It is a
matter of customer choice whether the unit is
replaced automatically after this time or when the
sensor fails to calibrate.
Toxic Gas CiTiceL 4-20 mA EasyCal Transmitter
