Operational Guide
29
Contaminated Buff er
“CONTAMINATED BUFFER” appears in order to alert
that the buff er could be contaminated. Refresh your
buff er and continue the calibration procedure.
Broken Temperature Sensor
If the temperature sensor should malfunction or
break at any time, a temperature of “25.0º C” will blink
on the second LCD line and the message “BROKEN
TEMPERATURE SENSOR” will appear on the third LCD
line after leaving calibration. The calibration will have
the compensation at 25 ºC.
Note
: If this occurs during logging “25 ºC !” will appear in the CSV fi le.
Good Laboratory Practice (GLP) refers to a quality control function used to
ensure uniformity of sensor calibrations and measurements. The dedicated
GLP key opens a fi le of the latest calibration information. Use the
qp
keys to
scroll the stored information. This includes the buff ers used, temperature of the
buff er, time and date of the last calibration, the sensor serial number and the
calculated off set and percent slope. This information is available in Basic and
Standard Modes. This information is also included with every data log. Newest
calibration points report as a solid number, older calibration data (that is still
used) will be displayed blinking.
If calibration has not been performed, the instrument
displays a blinking “NO CAL” message.
The pH calibration off set and slope (the GLP slope is
the average of the calibration slopes; the percentage is
referenced to the ideal slope value at the temperature
of calibration). The condition and response indicators
displayed are from the last calibration.
Pressing the
qp
keys, the last calibration date (yyyy.
mm.dd) together with the current reading is displayed.
Calibration
Messages
pH GLP
Information
