YOKOGAWA ZO21DW, User Manual, Page: 12 / 39

<2. INSTALLATION>
2-1
IM 11M03A02-00E
2. INSTALLATION
2.1 Installation Site
The following should be taken into consideration when installing the detector :
(1) Easy access to the detector for checking and maintenance work.
(2) A location in which the ambient temperature is not too high (below 70°C) and the terminal
box is not subject to radiant heat.
(3) A clean environment without any corrosive gases.
(4) No vibration.
2.2 Probe Insertion Hole
When preparing the probe insert hole, the following should be taken into consideration :
CAUTION
• The outside dimension of detector may vary depending on its options. Use a pipe that is
large enough for the detector.
• If the detector is mounted horizontally, the calibration gas inlet and reference gas inlet
should face downwards.
• When using the detector with pressure compensation, ensure that the flange gasket does
not block the reference gas outlet on the detector flange. If the flange gasket blocks the
outlet, the detector cannot conduct pressure compensation. Where necessary, make a
notch in the flange gasket.
• The sensor (zirconia cell) at the probe tip may deteriorate due to thermal shock if water
drops are allowed to fall on it, as it is always at high temperature.
(1) The detector probe tip should not be pointed upward.
Note : If the probe tip is placed upward, the cell (sensor) in the probe tip may deteriorate due to condensation.
(2) If the insertion probe length is more than 2.5 meters, the detector should be attached almost
vertically (no more than a 5 tilt).
(3) The detector probe should be situated almost at a right angle to the gas flow to be analyzed
or, at the very least, the probe tip should be on the down flow side.