5.
Select
pH
on the
Function
switch. When this position is selected the calibration settings are
locked (no further adjustment can be made to the buffer and slope values until the
pH Cal
position is re-selected on the
Function
switch).
6.
Immerse the electrode(s) and ATC probe in the unknown solution. The display will indicate
the pH value of the solution.
350 550/REV A/03-03
9
3.7 Performing Measurements
To perform measurements in pH, mV or temperature modes the following should be carried out:
1.
mV Measurement
a) Connect the electrode to the unit via the BNC socket on the rear panel. If a separate
reference electrode is to be used, this should be connected to the
Ref
socket.
b) Select
mV
mode on the
Function
switch. The display will show the electrode output
directly in mV.
2.
Temperature Measurement (using ATC)
a) Connect the optional ATC probe to the unit via the
Temp
socket on the rear panel.
b) Select
°C
on the
Function
switch. The display will show ATC probe temperature directly in
°C.
3.
Temperature Measurement (Manual)
a) If Manual temperature compensation is being used, the °C range should be selected on the
Function
switch.
b) Immerse the electrode into the solution and set to the solution temperature using the
Slope/Man Temp
control.
4.
pH Measurement
a) Perform a calibration sequence using manual or automatic temperature compensation.
b) Immerse the electrode(s) into the solution to be measured and note the results once the
reading has stabilised. (Refer to Section 3.6 for full details).
NOTE:
Ensure the pH/Reference probe combination are compatible with the samples being
measured. Non-compatibility may be indicated by drifting readings, noise or shortened
electrode life. During use the electrode must be rinsed between each measurement to
eliminate contamination of solutions. Excess droplets of solution may be removed by
gently blotting with filter paper or tissue.
For further details refer to Section 3.5-Good Practice Guidelines.