Hanna Instruments HI 98186 - Manual (Page 32)

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GOOD LABORATORY PRACTICE (GLP) GOOD LABORATORY PRACTICE (GLP) GOOD LABORATORY PRACTICE (GLP) GOOD LABORATORY PRACTICE (GLP) 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 DO calibration is stored for the user to review when
necessary.
EXPIRED CALIBRATION
The instrument is provided with a real time clock (RTC), in order to monitor the
time elapsed since the last DO calibration.
The real time clock is reset every time the instrument is calibrated and the
“expired calibration” status is triggered when the instrument detects a
calibration time out. The “CAL” “DUE” tags will start blinking to warn the
user that the instrument should be recalibrated.
The calibration time out can be set (see SETUP for details, page 33) from 1 to
7 days or can be disabled.
For example, if a 4 days time out has been selected, the instrument will issue
the alarm exactly 4 days after the last calibration.
However, if at any moment the expiration value is changed (e.g. to 5 days),
then the alarm will be immediately recalculated and appear 5 days after the
last calibration.
Notes:
• When the instrument is not calibrated or the calibration is cleared
(default values loaded) there is no “expired calibration”, and the
display always shows the “CAL” “DUE” tags blinking.
• When an abnormal condition in the RTC is detected, the instrument
forces the “expired calibration” status.
LAST DO CALIBRATION DATA
The last DO calibration data is stored automatically after a successful calibra-
tion. To view the last calibration data, press GLP when the instrument is in the
DO, BOD, OUR or SOUR measurement mode.
The instrument will display a lot of data including calibration standard,
salinity, pressure and temperature.
Note: “Not user calibration” message is displayed if the calibration was
cleared or the instrument hasn’t been calibrated for dissolved oxygen.