Michell Instruments WM281, Руководство пользователя

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WM281/291 User’s Manual
4 97463 Issue 1, July 2014
INSTALLATION
2.3 Element Filter Assembly
The fi lter is a fundamental element for a relative humidity transmitter, ensuring excellent
protection against dust pollution and high-speed air fl ow, and a good level of resistance
against chemical pollutants which are harmful for the sensor.
The fi lter allows the sensor to ‘breathe’ the humidity contained in the environment to
be measured and it is therefore very important to keep it clean.
The WM281/291 Transmitters can be equipped with the following fi lter models:
K7 Standard - Delrin cap with steel mesh fi lter for use in environments which are
relatively clean and where there is poor ventilation.
H2 Sintered steel fi lter for use in dusty environments.
J2
Sintered steel fi lter with PTFE coating for use in environments where there is a risk
of saturation and/or where aggressive chemical substances (solvents and acids) are
present.
Z7 Delrin cap with PTFE fi lter.
2.4 Wall Mounting
It is recommended that the WM281/291 Transmitters are installed with the measurement
probe facing downwards so as to minimize the propagation of heat between the
transmitter housing and the measuring element.
Figure 2
WM291