Metrohm 2.850.9110, Manual

Page: 21 / 44

￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭ 3 Installation
2.850.9110 IC Amperometric Detector
￭￭￭￭￭￭￭￭
13
In the Workplace program part:
￭
Load the method.
￭
In the Watch window , display the Current channel with at least
three decimal places.
5 Carrying out the test
In the Manual program part:
￭
Set all components of the IC instrument to inactive, particularly
the high-pressure pump(s).
￭
On the tab of the detector, switch on the dummy cell with
[Apply] .
After no more than one minute, the detector signal should level
off at 2.667 nA ± 7%. Noise should not exceed 0.005 nA.
￭
Switch the dummy cell off with [Cell Off] .
With the dummy cell switched off and the detector hardware still
running, the signal should drop below an absolute value of 1 nA,
and noise should be limited to the third decimal place.
Exactly even signals may indicate that new detector data is not
correctly transmitted.
6 Removing the dummy cell
￭
Pull out the electrode connection cables from the connectors AE ,
WE and RE of the dummy cell.
￭
Remove the dummy cell from the tray.
The dummy cell incorporates a resistor (300 M Ω ) and a capacitor (100 nF)
connected in parallel. If, in DC mode, a potential of 0.8 V is applied, then
a current of 2.667 nA (± 7%) is measured in the dummy cell. The capaci-
tor simulates a well-working measuring cell.
3.3.2 Testing the leak sensor
The leak sensor should not respond during the start-up. If the leak sensor
nevertheless does respond during the start-up, you will find information
for eliminating the problem in Chapter
(see chapter 5, page 24) .
To check whether the leak sensor is functioning, proceed as follows:
Testing the leak sensor
1 Hold a cloth moistened with eluent or tap water on the two contacts
of the leak sensor
(1- 7 ) .
The leak sensor of the detector responds.
If the leak sensor does not respond, please request Metrohm Service.