Sensor Installation; Environmental Monitoring; Monitoring A Flowing Sample - Michell Instruments Optidew User Manual

Optidew User's Manual

2.5. Sensor Installation

The dew-point sensor contains the optical system and the chilled mirror. It is fitted with a
12-pin M12 connector to allow easy and secure connection to the instrument using the
supplied sensor cable.
The available options for sensor installation are:
• via a permanently installed sample port into which the remote sensor can be inserted or
• via a sensor block immediately attached to the sensor around which the sample circulates or
• in an ambient environment where the sample is diffusing through the sensor.
NOTE: Ensure that the mirror surface is cleaned before installation. See Section 6
(Maintenance) for cleaning details.
Connect the remote sensor cable to the sensor and to the instrument via the connector on
the rear panel. The connector is a standard M12. Align the locating pin with the slot on the
socket and press the connector into place. Rotate the outer collar of the cable-mounted part
in a clockwise direction until finger tight.
If exchanging the sensor, refer to section 6.2.

2.5.1. Environmental monitoring

If the instrument is to monitor the conditions in an environment, the sensor must be located
in a representative position, i.e. not under an air conditioning vent.
A sensor wall mounting bracket is available to conveniently secure the sensor to a wall or
panel.
NOTE: It is recommended that the sensor is fitted with the porous aluminium
guard to baffle it from flowing air currents.

2.5.2. Monitoring a flowing sample

If the sensor is installed within a sealed gas system, it must be fixed securely without any
possibility of leaks. Ensure that the sample flow across the sensor is correctly regulated.
The gas connections for the remote sensor are either via a permanently installed sample port
into which the remote sensor can be inserted or via a sensor block immediately attached to the
sensor around which the sample circulates. Gas sample entry into the sensor block is via
couplings that can be installed into the provided ⅛" NPT female threads. A bonded seal is
provided to fill the connection between the sensor and the block.
Ensure that all connections to and from the sensor block are made with appropriate materials
and fittings for moisture measurement. For guidance on suitable apparatus, see section 4.3.
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