Yokogawa GD40 Gas Density Detector - Manual (Page 24)

<2. Installation, Wiring and Piping>
2-1
IM 11T3E1-01E
2. INSTALLATION, WIRING AND PIPING
The GD402 Gas Density Meter is thoroughly inspected at the factory and carefully packed to
ensure the equipment does not suffer any damage during transportation.
The package should also be handled with care when unpacking to prevent the equipment from
undergoing severe mechanical shock. After unpacking, visually check the equipment to ensure
that it is free from any damage.
Although the detector has no controls on it, it may need to be accessed for inspection or for other
reasons. Install the detector in a location as close as possible to where the gas is sampled and
where maintenance can be easily carried out. The converter has a display with controls on it;
thus, you should install it so that the keys are positioned directly in front of you when working.
Note that there must be a clearance of at least 400 mm at the back of the converter GD402G,
GD402T, GD402V and GD402R since cables are wired to the back by removing the screwed
rear cover.
2.1 Installing the Detector
The GD40 detector is an explosion-proof with intrinsically safe sensor instrument. Install the
detector in a location where the following conditions are satisfied.
2.1.1 Selecting the Location
l Explosion-proof construction
Before installing the detector in an explosion-hazardous area, ensure that the area conforms to
the explosion-proof code noted above.
l No corrosive gases
Corrosive gases are not desirable because they may damage the electrical components in the
detector.
l Slight mechanical vibration
Although the detector is vibration-resistant, vibration may loosen the connections of the external
wiring.
l No exposure to direct sunlight
Exposure to direct sunlight may raise the temperature in the detector to abnormal levels, and
should therefore be avoided. Note that such abnormal temperature levels can also result from
heat irradiated from high-temperature equipment around the detector.
l Humidity maintained between 5% and 95 %RH
Avoid choosing a location that is likely to be exposed to abnormally high or low humidity over a
prolonged period. It is recommended that the detector be used at a humidity between 25% and
85 % RH.
l No exposure to rain water
Even though the detector is rainproof, whenever possible install it where it is protected from water
splashes. The reasoning for this is that the detector cover may need to be removed for mainte-
nance or for other reasons.
l Altitude of installation site is lower than 2,000 m.