Installation Completion Check List; Power; Check The Purge Gas Supply; Instrument Clock Setting - Hach ORBISPHERE 3654 User Manual

3.8 Installation completion check list

3.8.1 Power

The instrument is designed to work on battery power or an external power supply. If battery
power should drop, a [LO BAT] warning appears in the instrument LCD's top left corner, and
they should be replaced.
If using an external power supply, ensure that this is clean, otherwise it may result in unstable
measurements.

3.8.2 Check the purge gas supply

It is critical that the TC sensor has a supply of purge gas before operating the system. The TC
sensor, when exposed to a liquid sample, could be damaged if the instrument purge gas
cylinder is empty. At the same time, it is also critical that the instrument has a power supply to
ensure the purge gas is supplied to the sensor on a regular basis. The system purges the
sensor for 4 seconds every 20 seconds during normal measurement mode, and every 17
minutes during standby mode.
A small, pressurized cylinder at the bottom of the instrument supplies purge gas to the sensor.
The purge gas required is:
• N
• CO
Verify that the purge gas is flowing at more than four bubbles during the purge cycle, by placing
the purge gas exit tubing into water.
Note: You must supply power constantly to the instrument, since it purges the sensor continuously while
power is on. When you put the instrument in standby, it still maintains the purge gas supply to the sensor.
Thus, make certain to supply battery or optional external DC power constantly if the instrument is in standby
and the sensor is exposed to a sample. The batteries will provide about three weeks of power for purging
while the instrument is off.

3.8.3 Instrument clock setting

If you use the instrument to store measurements for downloading to a PC, you should verify the
date and time settings of the instrument's internal clock. Refer to

3.8.4 Barometric pressure setting

The internal barometric pressure sensor has been factory calibrated but should be verified
on-site with a precision certified barometer, and corrected if necessary. For instructions on how
to do this, please refer to

3.8.5 Sensor membrane

Check that the membrane has been installed correctly, and is flat, tight, and wrinkle free.

3.8.6 Flow chamber

The flow chamber inlet and outlet should be free of any obstructions. The model 32013A flow
chamber, for dissolved N
32015 flow chamber for H
Dissolved gas measurements
Adjust the sample flow rate using the needle valve on the exit. When analyzing carbonated
beverages, sufficient pressure must be provided to avoid degassing of the beverage during its
passage through the flow chamber. Check for the absence of bubbles in the inlet tubing.
Gaseous measurements
Place the outlet tubing in a container of water, ensuring that the flow chamber outlet is
unobstructed (on the 32013A flow chamber, open the outlet valve completely). Then, adjust the
inlet sample flow valve (main supply) to obtain one bubble per second at the outlet.
purge for H measurements.
2 2
purge for N or H measurements.
2 2 2
Barometric pressure sensor calibration on page
measurements, has a flow adjustment valve on the outlet. The model
2
measurements has no valve.
2
Installation
Clock settings on page 46.
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