The sensor and measuring instrument are connected by a cable and two 10 pin connectors. The
standard sensor cable length is 3 meters, but extension cables of up to 1,000 meters are available,
still retaining the same signal sensitivity. If the model 28117 pressure sensor is used, the maximum
cable length is 50 meters.
Ensure that the sensor will be mounted:
• perpendicular to the pipe
• on a horizontal pipe section (or on flow-ascending vertical pipe)
• minimum of 15 meters away from the pump's discharge side
• in a place where the sample flow is stable and rapid, and as far as possible from:
• valves
• pipe bends
• the suction side of any pumps
• a CO2 injection system or similar
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.
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.
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).
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:
• 28117 Pressure sensor 0 - 5 bar absolute
• 28117C Pressure sensor 0 - 1 bar absolute
CAUTION
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).
English 9
