Hanna Instruments HI 3512 User Manual

Page 37

GLP is a set of functions that allows storage and retrieval of data
regarding the maintenance and status of the electrode.

All data regarding pH, Rel mV, ISE, EC or Salinity 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 pH 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” warning 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 40) 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 calibration is cleared

(default values loaded) there is no “expired calibration”,
and the display always shows the

“CAL DUE” warning

blinking.

• When an abnormal condition in the RTC (Real Time Clock) is

detected, the instrument forces the “expired calibration”
status.

LAST pH CALIBRATION DATA

The last pH calibration data is stored automatically after a successful
calibration.
To view the pH calibration data, press

GLP function key when the

instrument is in the pH measurement mode. If

GLP function key is not

displayed press

MENU key.

The instrument will display a lot of data including calibration buffer,
offset, slope, electrode condition.

GOOD LABORATORY PRACTICE (GLP)