Metrohm 827 pH lab - Manual (Page 40)

6.1 pH measurement (pH mode)
32
826/827 pH meter, Instructions for Use
The other stored buffer tables are described in Section 9.3. During the
calibration the pH meter shows the type and temperature-specific pH
value of the recognized buffer. For temperatures within the 5 °C steps
the pH value is linearly interpolated.
buff.type: special
If you would like to use different buffers from those described,
then you require the exact pH value of each buffer at the tempera-
ture used for calibration. These pH values can be entered here.
During the calibration they can again be adapted before each
measurement.
A general rule is that you can only calibrate in defined temperature
ranges, as otherwise the following error message appears:
buffer not defined
6.1.3 Limits
param
:
├
cal.limits
: ├
lo.lim.slope
├
up lim.slope
├
lo.lim.pH(0)
└
up lim.pH(0)
The most important calibration data such as slope and pH(0) must be
within the limits defined here in order to be adopted automatically.
lo.lim.slope 1.0...95.0...999.9 %
up lim.slope 1.0...103.0...999.9 %
lo.lim.pH(0) 0.00...6.40...99.99
up lim.pH(0) 0.00...8.00...99.99
If one of the values of the calibration data lies outside these limits then
at the end of the calibration the following message is displayed:
cal. out of limits
You can accept these calibration data nevertheless with <OK> or you
can reject them with <QUIT>.