Installation Checklist - Hach ORBISPHERE 3654 Manuel D'utilisation De Base

Make sure you install a fully charged set of batteries, or connect the instrument to an external power
source before switching the instrument on and exposing the sensor's membrane to any liquid. Refer
to External power supply (optional)

4.9 Installation checklist

4.9.1 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.
4.9.2 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 purge for H measurements
2 2
• CO purge for N or H
2 2
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.
4.9.3 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, as described in
4.9.4 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 Barometric pressure sensor calibration
4.9.5 Sensor membrane
Check that the membrane has been installed correctly, and is flat, tight, and wrinkle free.
4.9.6 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. If necessary, adjust the pressure using the flow adjustment valve.
• 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.
12 English
on page 9.
measurements
2
measurements, has a flow adjustment valve on the outlet. The model
2
measurements has no valve.
2
Clock settings
on page 21.
on page 28.