Push the installation tool firmly downwards. This clasps the mounting ring onto the
sensor head, folding the membrane over the sensor tip.
Remove the installation tool and guiding sleeve.
Visually check for correct ring placement, try to push it down with your fingers.
Check that the membrane is tight, with no wrinkles.
Note: Once installed, a membrane cannot be reused. Avoid touching membranes with bare fingers, as
this may affect its sensitivity.
Clean and dry the protection cap ready for installation.
Replace the O-ring inside the protection cap with a new one. Tighten the protection cap
finger tight.
Then, complete the process using the tool provided in the maintenance kit. Insert into
each of the four holes in turn, and tighten as far as possible. Tighten each hole only
once.
Finally replace the flow chamber, by gently lowering it onto the sensor and guiding the thermistor and
purge gas air duct on the sensor into the two holes in the flow chamber base. Turn the flow chamber
locking nut clockwise to secure it in place.
Check that the membrane has not been damaged. The alarm message “
ERR
” will be displayed on
your analyzer if the membrane leaks in any way.
Troubleshooting
Troubleshooting - Instrument
If your analyzer is behaving strangely (failing to calibrate, giving inappropriate measurement values,
etc.) and you have attempted to rectify the problem by servicing the sensor (for instructions, see
on page 20) but to no avail, you may wish to use the Hach 3658
Troubleshooting
menu to make sure that the instrument is configured correctly for your application,
and is in good working order.
The instrument must be connected to your PC and placed in measurement mode to perform these
tests.
Serial test
Normally, the analyzer will inform you of a disconnected RS-232 (serial) link when appropriate.
However, you can confirm a good connection using the
Troubleshooting
,
Serial Link Test
by
echoing a test message via the instrument.
Enter text characters in the
Text to be sent
box, then click
Send
. If the serial link is operating
correctly, the exact same text will be displayed back from the instrument in the
Echo
box. Choose
Cancel
to exit from this test box.
Keyboard test
The
Troubleshooting
,
Keyboard Test
will reveal whether all the analyzer buttons are functioning
correctly.
Press any one of the instrument's buttons (
except
the
ON/OFF
button) for a full second or more. The
appropriate square on-screen should darken. Choose
Cancel
to exit from this test box.
Display test
Choosing
Troubleshooting
,
Display Test
lets you perform a one-way communication between
computer and instrument.
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