Riken Keiki GD-1DOX-AS, Operating Manual

Page: 19 / 34

4 How to Use 4-7. How to tube
- 17 -
CAUTION
•
The longer the tube of the GAS IN is, the longer it takes for a gas to reach the detector.
Because some gases have a highly adsorptive property for the tube, resulting in a slow
response and a lower reading than the actual value, the length of the GAS IN tube must be
minimized.
• When the humidity in the sampling point is high, condensation may be formed inside of the
tube. Make sure to avoid condensation when using a gas which is dissolved into water and
corrodes contacted materials, such as a strong acid gas, because it is undetectable and
furthermore may corrode internal parts. Also avoid an excessive U-shaped or V-shaped tube
piping.
• Determine the inlet for the sample gas, considering the air flow of the sample gas line and the
gas generating process.
•
To remove dust, do not forget to attach a dust filter in the middle of the tube.
• You need to decide the length and material of the tube. Please contact RIKEN KEIKI for more
information.
WARNING
• The detector is designed to draw gases around it under the atmospheric pressure.
Be sure that excessive pressure is not applied to the sampling inlet and outlet (GAS IN, GAS
OUT) of the detector.
• Detected gases must be exhausted from the detected gas exhausting outlet (GAS OUT) to
which an exhaust tube is connected, to a point regarded as a safe place.
4-7. How to tube
The detector has a Rc1/8 thread inside of the sampling inlet/outlet (GAS IN, GAS OUT), the "PP" unions is
normally attached. Because their material varies depending on the gas to be used, please specify the
appropriate unions.
The compatible tube is a tube of Φ6 (OD) - Φ4 (ID). The tube must be installed with the supplied inners
and sleeves attached to prevent a leak.
When the tube is cut, its cut point has a smaller inner diameter. Use a file etc. to expand the inner diameter
of the cut point. To remove cut-dust remaining inside of the tube, blow compressed air into the tube before
connecting it to the detector.
Some sample gases have highly adsorptive or corrosive property. Select the tube material taking into
account of these precautions.
Be careful that the flow rate introduced to the detector is in the range of 0.8 - 2 L/min (the maximum
pressure inside the flow path and sensor parts is 10.13 kPa <gauge pressure>).