Elcometer 138 User Manual page 14

5 USING THE CONDUCTIVITY METER (continued)
Using manual calibration (Figure 6):
In manual calibration, customised calibration solutions with known
conductivity values can be used to calibrate the meter.
The table below shows acceptable conductivity ranges of calibration
solutions for each measuring range. Ensure the calibration solutions
used are within the given ranges.
Measuring Range
PU
LO
HI
AUTO
Always use fresh calibration standard solutions. Before you begin,
measure the conductivity value of the solution with a meter known to
be accurate. Prepare the solution in two beakers; one for rinsing and
the other for calibration. Rinse the electrode in pure water before
calibration.
1 Press the 'On/Off' button to switch the meter on. Make sure the
meter is in measuring mode.
2 Rinse the electrode with the calibration standard then dip the
electrode into the second beaker containing the calibration
standard. Swirl gently to create a homogenous sample and allow
time for the reading to stabilise.
3 Press 'INC' or 'DEC' to enter conductivity calibration mode. The
'CAL' indicator appears on the display. 'CAL' and '1.Pnt' are
briey displayed.
4 The upper display shows the measured conductivity reading of
the solution based on previous calibration (if any) and the lower
display shows the default (uncalibrated) conductivity reading.
'Er.1' is displayed if the reading is over range of the selected measuring

range of the tester or if the default (uncalibrated) reading is not within the
acceptable calibration standard range.
en-13
R
Acceptable Calibration Standard Range
2.0 - 200.0 µS/cm
200 - 2000 µS/cm
2.00 - 20.00 mS/cm
Select a calibration standard nearer to application
sample
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