15
GOOD LABORATORY PRACTICE (GLP)
GLP is a set of functions that allows storage and retrieval of data regarding the
maintenance and status of the electrode.
All data regarding last pH calibration (one, two or three-point) and Ion
calibration is stored for the user to review when necessary. This data includes
the following: calibration time stamp, offset (mV), average of pH slope (%) or
Ion slope (mV), calibration buffers and the time until a new calibration is
required (only for pH calibration).
CALIBRATION ALARM TIME-OUT
For pH calibration, HI 253 allows the user to set the number of days before the
next required calibration. This value can be set from 1 to 7 days. The default
setting is OFF (disabled).
The instrument checks if the time-out time has expired. If the time elapsed, the
“CAL” “INTV” tags will blink as a reminder.
Note: If the instrument was not calibrated, the “CAL” “INTV” tags will be
displayed even if the feature is disabled in SETUP menu.
LAST pH CALIBRATION DATA
Last pH calibration data is stored automatically after a successful calibration.
To view the pH calibration data, press GLP while in normal measurement
mode.
The instrument will display the time (hh:mm) of the last calibration.
Press the ARROW keys to view the next logged calibration parameter
(pressing the ºC key):
• The date (yyyy.mm.dd).
• The pH calibration offset.
