Hach-Lange ORBISPHERE 31xxx Installation and Maintenance - Manual (Page 22)

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Installation
4.3 Sensor insertion
• Insert the sensor straight into the flow chamber or socket.
• Hand tighten the attaching collar.
• Connect the sensor cable.
• Check for leaks; replace O-rings if product leaks are visible.
Micro volume flow chambers:
Do not twist the sensor when inserting it into a micro volume flow chamber. This rotation may
twist the membrane holding ring, thus changing the membrane position. This can modify the
membrane measuring conditions, and affect measurement precision.
Note: Check that the small O-ring at the bottom of the flow chamber is present during removal and
installation of the sensor, as it may stick to the sensor head and fall.
4.4 Sensor removal
• Shut off the sample flow and drain the sampling circuit of liquid or gas.
• Remove the sensor cable connected at the sensor end.
• Hold the sensor body in one hand to avoid rotation and unscrew the collar with the other.
• Pull the sensor straight out of the socket or flow chamber.
• Check that both O-rings remain in place inside the flow chambers.
• Install sensor storage cap and sensor base (to protect the connection).
4.5 Mounting accessories
Note: Check the spare part list at the end of this manual for ordering information.
4.5.1 External pressure sensor
The system can be fitted with an external pressure sensor. This enables a measurement of
fraction of gas under variable pressure conditions during gas phase measurement.
Figure 6 Sensor insertion
Two models are available, depending on the application:
• 28117 Pressure sensor 0 - 5 bar absolute
• 28117C Pressure sensor 0 - 1 bar absolute