User manual

4.5 Cleaning the conductivity flow cell in-place

Remove the pH electrode and install the dummy electrode in the pH

flow cell.

Pump a cleaning or sanitising agent through the flow cell. The

standard recommendation is to pump 1 M NaOH for 30 minutes

and then wash out with buffer.

4.6 Cleaning the conductivity flow cell off-line

If the conductivity measurements are not comparable to previous

results, the electrodes in the flow cell may be contaminated and

require cleaning. To clean the flow cell:

1 Pump 15 ml of 1 M NaOH at 1 ml/min through the flow cell

either by using a pump or a syringe.

2 Leave it for 15 minutes.

3 Rinse thoroughly with 50 ml distilled water.

Note: If the flow cell is totally blocked, the blockage can be removed

using a needle or a wire with a diameter less than 0.8 mm.

4.7 Changing the conductivity flow cell

The conductivity flow cell can be changed when required. Make sure

the monitor is switched off before disconnecting/connecting the cell

from the rear of the monitor housing.

If the cell is replaced with a new flow cell, the monitor must be

calibrated with the new cell constant value written on the flow cell

package. See section B.2 in Reference information. If the cell

constant is not known, it can be determined (see also section B.2 in

Reference information).

WARNING! NaOH is injurious to health. Avoid spillage.

Monitor UPC-900

User Manual 18-1125-55 Edition AE

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