Hanna Instruments HI 250 - Manual (Page 13)

13
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 calibration (one, two or three-point) is stored for the
user to review when necessary. This data includes the following: calibration
time stamp, offset (mV), slope (%), calibration buffers and the time until a
new calibration is required.
CALIBRATION ALARM TIME-OUT
HI 250 and HI 251 allow the user to set the number of days before the next
required pH calibration. This value can be set from 1 to 7 days. The default
setting is OFF (disabled).
The instruments check if the time-out time has expired. If the time elapsed, the
“CAL” “INTV” tags will blink as a reminder.
Note: If the instruments were not calibrated, the “CAL” “INTV” tags will be
displayed even if the feature is disabled in SETUP menu.
LAST CALIBRATION DATA
The last calibration data is stored automatically after a successful calibration.
To view the pH calibration data, press GLP while in normal measurement mode.
The instruments 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.
• The pH calibration slope (the GLP slope is the average of the calibration
slopes; the percentage is referred to the ideal value of 59.16 mV/pH).
TIME CAL
DATE CAL
CAL mV
% CAL