Metrohm 746 VA Trace Analyzer - Manual (Page 92)

4.1 Preparations
746 VA Trace Analyzer / 747 VA Stand
4-7
4 Testing stirrer
• Press the softkey . The stirrer is switched on, at the same
time the display for Stirrer switches to on and an asterisk * appears
in the softkey of the same name.
• Check whether the stirrer functions properly. If so, you can switch off
the stirrer by pressing the softkey .
• If the stirrer does not function properly, check its installation as described
in section 3.8 and then repeat the test.
Stirring serves to mix the analysis solution thoroughly. In determinations, the instruc-
tions STIR or TSTIR are used for this (see section 5.7.3).
5 Testing DME
• Press the softkey . The dropping mercury electrode DME is
switched on, at the same time the display for DME switches to on.dt
and an asterisk * appears in the softkey of the same name.
• Check whether the DME functions properly. The mercury must flow
slowly out of the capillary of the MME and the drop time be ca. 3 s. If this
is the case, you can switch off the DME by pressing the softkey .
• If the DME does not function properly, check the installation of the MME
as described in section 3.4 and then repeat the test.
You will find further information regarding the DME under the instruction DME in section
5.7.3.
6 Testing HMDE
• Press the softkey . The hanging mercury drop electrode HMDE is
switched on, at the same time the display for HMDE switches briefly to on
and an asterisk * appears in the softkey of the same name.
• Check whether the HMDE functions properly. Each time the softkey
is pressed, a mercury drop should be formed. Dislodge the mer-
cury drop formed by lightly tapping the MME with your finger and check
that the mercury ceases to flow.
• If the HMDE does not function properly, check the installation of the
MME as described in section 3.4 and then repeat the test.
You will find further information regarding the HMDE under the instruction HMDE in
section 5.7.3.
7 Switch to subpage "Settings"
• Press the softkey . The top part of the "STAND" dialog page
remains the same, but different softkeys appear: