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4.2 Calibration Notes
1.
A Primary Calibration should be performed at least weekly. In applications
where the reference electrode junction can become blocked, such as dairy
products, mining slurries etc, a Primary Calibration may have to be done
daily.
2.
A full Primary and Secondary Calibration should be performed at least
monthly. Of course, more frequent calibration will result in greater
confidence in results.
3.
All calibration information is retained in memory when the
WP-90
is
switched off, even when the battery is removed. This information can be
recalled or printed later using the GLP function (see section 9).
4.
The
WP-90
displays the value of the standard to which it will attempt to
calibrate. Ensure that the standard value displayed corresponds to the
standard that you are using. Alter the set-up if necessary (see section 3)
4.3 Calibration Messages
1.
If a Primary Calibration has been successfully performed, the
WP-90
will
display the following message, and the offset value of the sensor. For
example…
Primary Cal. OK
Offset= 1.0mV
2.
If a Secondary Calibration has been successfully performed, the
WP-90
will
display the following message, and the slope value of the sensor. For
example…
Sec Cal. OK
Slope= 99.0%
3.
If a Secondary Calibration has failed, the
WP-90
will display the following
message, and the failed span value of the sensor. For example…
Sec Cal. Failed
Slope= 49.0%
Notes
1.
The Offset range is unlimited, as long as the reading is not over-ranged. This
is to allow for the large variety of Ion Selective Electrodes available.
2.
The allowable Slope range is 50.0% to 110.0%. This range is ample to allow
for correctly functioning Ion Selective Electrodes.