Hach ORBISPHERE 3654 Allgemeines Benutzerhandbuch Seite 9

The hole in the side and near the base of the sensor is the purge gas exit. To check the purge gas
flow rate, push the supplied nylon tubing into this hole, to its limit. To disconnect it again, press on
the ring surrounding the tube and pull out.
To check the purge gas flow rate, immerse the end of this tubing in water and switch on the
instrument. Gas should flow intermittently out of the tube.
Note: During normal operation, and especially when the instrument is in standby mode, ensure that the exit of the
purge gas tube is exposed to the atmosphere and not in contact with any liquid or hard surface.
Connections
External power supply (optional)
The instrument is usually powered by the batteries supplied. You can, however, power it from an
external power source using the model 32939 power supply adaptor as illustrated in
Figure 3 Model 32939 power supply
Connect the male LEMO-6 plug on the power supply adapter, to the RS-232 connector on the right
side of the instrument. The female LEMO-6 plug can then be used to connect to your PC using the
standard RS-232 cable supplied with the instrument.
Plug the transformer into your mains power supply using the cable supplied.
Note: If the external power supply is not clean, this may result in unstable measurements.
Instrument - PC connection
An RS-232 cable is supplied with the instrument, with a 6-pin LEMO plug on one end and a 9-pin D-
Type plug on the other.
Connection LEMO-6 Pin Description
Pin 1 Transmitted data (TXD)
Pin 2 Received data (RXD)
Pin 3 CTS
Pin 4 RTS
Pin 5 Not used
Pin 6 Ground
Figure 3.
English 9