Hach ORBISPHERE 3658 Basic User Manual page 6

• The Hach 3658 software on a CD and a PC communications cable
• Two C-type batteries
• A sensor recharge kit in a plastic case containing materials to maintain and service your sensor
Instrument overview
Figure 1 ORBISPHERE 3658 portable CO
1 Sample flow inlet
2 Flow rate adjustment valve
3 Flow chamber
4 Sample flow outlet
5 Pressure relief valve
6 RS-232 port and DC power connection
The ORBISPHERE 3658 portable analyzer accurately measures carbon dioxide in dissolved phase,
using a thermal conductivity sensor. The analyzer can store up to 500 measurements, and its
rechargeable batteries allow up to 15 hours continuous operation.
Before each measurement the TC sensor is automatically flushed with ambient dried air supplied by
the integrated pump and condenser, and sucked into the flow chamber through the purge gas inlet
(No. 8 in Figure 1) before being released back into the atmosphere via the purge gas outlet (No.
11 in Figure 1).
After each purge, the gas to be measured diffuses from the liquid sample through the membrane,
changing the thermal conductivity of the gas surrounding the detector. As each gas has its own
specific thermal conductivity the measurement is not affected by the presence of other gases unlike
traditional total pressure/temperature methods. The liquid sample flow rate is adjustable using the
flow rate adjustment valve (No. 2 in
Both the membrane-covered TC sensor (No. 10 in
are shipped pre-installed on the instrument. It will, however, be necessary to remove the flow
chamber when servicing the sensor.
3658 PC software installation
Install the Hach 3658 software by inserting the accompanying CD into your PC and running the
SetUp program. Simply follow the on-screen instructions.
When finished, a new directory HU\HU3658 is created on your hard disk containing the software and
help files.
6 English
analyzer - front and rear view
2
7 Battery cap
8 Purge gas (air) inlet
9 Flow chamber locking nut
10 TC sensor
11 Purge gas (air) outlet
12 Sensor locking pin
Figure 1) integrated into the flow chamber.
Figure 1) and the flow chamber (No. 3 in Figure 1)