Calibration; Selecting A Standard; Performing A Calibration; Sample Measurement - Mettler Toledo EL30 Mode D'emploi

Operating the conductivity meter
4.2

Calibration

4.2.1

Selecting a standard

When using the Education Line conductivity meter, you have to select a standard for calibration.
Press the Setup key (EL30) or press and hold the Mode/Setup key (EL3) until the setup icon appears
on the display and the current standard blinks. Use  or  to select another standard and press Read
to confirm your selection. Press Exit to leave the setup mode.
The three predefined standards are:
- 84 μS/cm
- 43μS/cm
- 2.88 mS/cm
Tables for automatic temperature compensation are programmed in the meter for each standard (see
also appendix).
4.2.2

Performing a calibration

Place the conductivity sensor in the defined calibration standard and press Cal.
The calibration icon and the measurement icon appear on the display. The meter endpoints according
to the preselected endpoint mode after the signal has stabilized or after pressing Read. The standard
value at the measurement temperature is displayed and stored; the measurement icon disappears from
the display.
The cell constant is shown on the display for 3 seconds. To reject the calibration, press Exit, before the
meter returns automatically after 3 seconds to the measurement screen.
Note:
To ensure the most accurate conductivity readings, you should verify your cell constant with a standard
solution once a day and recalibrate if necessary. Use always fresh standards.
4.3

Sample measurement

Place the conductivity sensor in the sample and press Read to start the measurement: the measurement
icon appears on the display and the decimal point blinks. The display shows the conductivity of the
sample. The automatic endpoint A is the default setting of the meter. When the signal has stabilized,
the display freezes automatically, and
By pressing and holding Read, you can switch between the Auto and Manual endpoint mode. To manually
endpoint a measurement, press Read: the display freezes and
Stability criterion for conductivity measurement – The sensor input signal of the meter may not change
by more than 0.4% from the measured average conductivity of the probe in 6 seconds.
8
Five_cond_edu.indb 8
appears.
appears.
METTLER TOLEDO Education Line conductivity meter
13.03.2007 16:28:04