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GOOD LABORATORY PRACTICE (GLP)
GLP is a set of functions that allows the storage or retrieval (when
necessary) of data regarding the maintenance and status of the
electrode. The meter can automatically analyze the data and advise
the user with a clear message if a problem is found.
PROBE LIFE VERIFICATION
At the end of calibration, the meter checks if the electrode offset is within
±30 mV range and the slope between 53.5 and 62 mV/pH. If the
values are not within these limits, the message "old probe" scrolls across
the LCD. The electrode is still working, but it is necessary to perform a
cleaning procedure (see "Electrode cleaning and maintenance" section)
or replace it.
If the offset is outside the ±60 mV range or the slope is outside the
40 to 70 mV/pH interval, the "dead probe" message will scroll across
the LCD; the reading will blink on the primary LCD to warn the user
that it is not reliable.
ELECTRODE IDENTIFICATION
At start-up the meter checks if the electrode is connected. If not, the
message "no probe" scrolls across the LCD and dashes ("----") are
displayed in place of the reading.
If the meter detects a "dead probe" situation, the reading will blink.
CALIBRATION ALARM TIME-OUT
The calibration alarm time-out is available only for pH calibration.
It is possible to set (through setup code 10) the number of days
before the next required calibration procedure. User can set a value
from 01 to 99 days. The default value is 07. Set the parameter to
"OFF" to disable this feature.
When turned on, the meter checks if the time-
out time has expired. If yes, the message "Cal
date" scrolls across the LCD and the "DATE"
tag blinks as a reminder.
LAST CALIBRATION DATA
Last calibration data are automatically stored after a successful
calibration and they can be displayed by pressing the CAL DATA key.
To view the pH calibration data
• Press (ALT+) CAL DATA when the meter dis-
plays pH reading.
ORP MEASUREMENTS
Connect the ORP electrode to the meter and press the ON/OFF key.
The meter automatically sets the mV range.
If the electrode is not connected the LCD will display the "no probe"
message and then dashes.
To take ORP measurements, remove the electrode protective cap and
simply submerge the tip (4 cm/1½") of the electrode in the solution
to be tested, stir gently and allow for the reading to stabilize.
Note:
The ORP electrodes are not provided with the temperature
sensor.
By continuously pressing the DISPLAY key the following information
will be displayed on the primary LCD:
• Time
• Day / Month
• Year
Pressing DISPLAY again, the meter returns to mV reading.
Note:
If measurements are taken successively in different samples, it
is recommended to rinse the electrode thoroughly with deion-
ized water or, if not available, tap water first and then with
some of the next sample to condition the electrode before
immersing it in the sample to be tested.
TEMPERATURE MEASUREMENTS
The temperature sensor is integrated in the pH electrode.
Immerse the pH electrode in the solution, wait a few minutes for the
temperature to stabilize and press the ON/OFF key. The temperature
will be displayed on the secondary LCD.
Note:
If temperature measurement is out of range the LCD will
display "- - -".