Hach ORBISPHERE 31 Série Manuel D'utilisation Simplifié page 10

• a CO injection system or similar
2
Note: There may be situations where not all the above conditions can be met. If this is the case, or you have any
concerns, please consult your Hach Lange representative to appraise the situation and define the best applicable
solution.
5.3 Sensor insertion
• Insert the sensor straight into the flow chamber or socket. Do not twist the sensor.
• Hand tighten the attaching collar.
• Connect the sensor cable.
• Check for leaks; replace O-rings if product leaks are visible.
Instructions for micro volume flow chambers
Do not twist the sensor when inserting it into a micro volume flow chamber. This rotation may twist
the protection cap, thus changing the membrane position. This can modify the membrane measuring
conditions, and affect measurement precision.
5.4 Sensor removal
• If not using the ORBISPHERE 32003 insertion/extraction valve you will need to shut off the sample
flow and drain the sampling circuit of liquid.
• 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 hand.
• Pull the sensor straight out of the socket or flow chamber.
• Install the sensor storage cap and sensor base (to protect the connection).
5.5 External pressure sensor
The system can be fitted with an external pressure sensor. This enables a measure of fraction of gas
under variable pressure conditions during gas phase measurement.
Two models are available, depending on applied pressure:
• 28117GP Pressure sensor 0–3.5 bar absolute
• 28117C Pressure sensor 0–1 bar absolute
Do NOT exceed the pressure range of the sensor. This would permanently deform the sensor
membrane, thus delivering incorrect pressure values in the future.
The external sensor connects to the ORBISPHERE measuring equipment with a 1 meter cable and a
4 pin connector (an optional extension cable can be used, but total length should not exceed
50 meters).
The external pressure sensor can be installed in the model 32002.xxx multi parameter flow chamber.
It is held in place by a blue threaded collar. Tightness is assured by the O-ring on the sensor seat.
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