Radiometer Analytical MeterLab PHM220 Mode D'emploi page 36

Accept Time
60s
Min ZeropH Limit
5.8
Max ZeropH Limit
7.5
Min Sens. Limit
95
Max Sens. Limit
102
Calibrate every
24 hours
Return to the first Edit display by pressing the up arrow key or leave the Edit
mode by pressing the Mode, Cal, Sample, pH/mV or GLP key.
36
Chapter 3
In the example shown, the signal will be accepted
and locked on the display after 60 seconds whether
it is stable or not. Enter "0" if you only want the
electrode signal to be accepted when it is stable.
Range available: 0 to 9999 seconds.
The zero pH is an electrode characteristic which is
determined during the first step of a calibration.
Zero pH is defined as the pH at which the potential
pH
of the electrode system equals zero. It depends upon
the potential of the reference electrode used and the
potential of the glass electrode. These potentials may
pH
vary over time, causing the zero pH of the electrode
to change. Calibration must be performed regularly to
ensure reliable measurements. Normally, limits of
pH 5.8 and 7.5 are appropriate.
Range available: 0.1 to 14.0 pH
The sensitvity is found during the second step of a
2 or 3-point calibration. The sensitivity is a measure of
%
the condition of the electrode and is given as a
percentage of the theoretical slope of the calibration
curve. Normally, limits of 95% and 102% are
%
appropriate.
Range available: 10 to 110%
The PHM220 will prompt you to perform a new
calibration if the current calibration is older than,
for example, 24 hours.
Range available: 1 to 999 hours