Hach ORBISPHERE 31x9 Series Basic User Manual page 9

1. The sensor head is protected by a screw-on black plastic storage cap. This cap should be
removed.
2. Once the storage cap has been removed, an orange sticker will be visible informing you not to
remove the protection cap. This is because the sensor has already been checked and calibrated
prior to shipping, and no sensor maintenance or membrane change is required prior to first use.
However, this label must be removed.
3. Attach the two small identification clips (stamped with the letter "T") to each end of the sensor
cable so they are clearly visible. These clips indicate this is a TC sensor, so when connecting to a
multi-channel analyzer, care must be taken to connect it to the TC measurement board.
4. Make sure that the gas purge supply is set to ON before the sensor is installed in a line or a flow
chamber that contains liquid or humidity. If the sensor does not have purge gas supply when it is
in aqueous liquid or condensing humidity, permanent damage to the sensing element will occur.
Sensor positioning
Unless the sensor is part of the ORBISPHERE equipment that includes it, the sensor must be
installed in an ORBISPHERE socket or flow chamber, that allows the contact with the sample fluid to
be analyzed.
The sensor and measuring instrument are connected by a cable and 10 pin connector. The standard
sensor cable length is 3 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 CO injection system or similar
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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 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
• Shut off the sample flow and drain the sampling circuit from liquid or gas pressure.
• Remove the sensor cables connected at the sensor side.
• Remove the purge gas connections.
• Hold the sensor body in one hand to avoid rotation, and unscrew the collar with other hand.
• Pull the sensor straight out of its socket, or flow chamber.
• Check that both O-rings remain in place inside the flow chambers.
• Install the storage cap on the sensor.
English 9