Elcometer 138 User Manual page 11

5 USING THE CONDUCTIVITY METER (continued)
5.6 CONDUCTIVITY CALIBRATION
The meter must be calibrated on a regular basis to ensure accurate
results. Calibration can be manual or automatic; 1 point or multi-point.
The factory default setting is automatic, 1 point calibration. In
automatic calibration, the meter automatically detects and veries
known conductivity standard solutions. In manual calibration, non
standard solution which may be specic to your application can be
used.
Note: This user guide explains the 1 point calibration technique only as only one
calibration solution is supplied with the kit; multi-point calibration requires
calibration solutions of different values. For further information on multi-point
calibration, contact Elcometer for a copy of the full Elcometer 138E operating
instructions.
To enable / disable auto calibration and select 1 point calibration
(Figure 4):
1 With the meter switched off, press and hold the 'INC' button, then
switch the meter on. Release the 'INC' button.
2 The meter goes to auto calibration selection mode. The lower
display shows 'A.CAL' and the upper display blinks the current
choice; 'Yes' or 'No'. Press 'INC' or 'DEC' to select 'Yes' and
enable auto calibration or 'No', to disable auto calibration.
Press '°C/°F' to skip this setting without confirming changes.

Press '°C/°F' twice to return to the measurement mode without confirming

changes.
3 Press 'HOLD ENT' to confirm the selection; 'CO' is displayed.
4 The meter goes into 1 point calibration selection mode. The
lower display shows '1.Pnt' and the upper display blinks the
current choice; 'Yes' or 'No'. Press 'INC' or 'DEC' to select 'Yes'
and enable 1 point calibration.
Press '°C/°F' to skip this setting without confirming changes.

Press '°C/°F' twice to return to the measurement mode without confirming

changes.
5 Press 'HOLD ENT' to confirm the selection; 'CO' is displayed for
a few seconds followed by the power-up sequence. The meter
goes into measurement mode.
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