Conductivity Measurement - Apera Instruments Premium Series User Manual

Calibration Indication Icon
For conductivity calibration solutions, we recommend replacing new solutions after 5 times of use to
keep the standard solution's accuracy. NEVER pour back used calibration solutions into the solution
bottles.

7. Conductivity Measurement

7.1 Short press to turn on the tester. Rinse the probe in pure water and shake off excess water.
Dip the probe into your sample solution, make a quick stir, and hold still. Record the reading
as your measurement after it is fully stabilized (
from conductivity to TDS, and Salinity. Or if you turn on the Auto-Hold function (refer to Section
10.2.b), the reading will be automatically locked when it's stable for more than 10 seconds. Short
press to cancel the Auto-Hold and keep measuring.
7.2 Unit Conversion
a) 1000 µS/cm = 1 mS/cm = 1 EC (In conductivity mode, the unit will automatically turn from µS to mS if
the reading is greater than 1999 µS, meaning you will only see 2.XX mS instead of 2XXX µS)
b) 1000 ppm = 1 ppt (In TDS mode, the unit will automatically turn from ppm to ppt if the reading is
greater than 999 ppm, meaning you will only see 1.XX ppt instead of 1XXX ppm)
c) The TDS and Salinity values are converted from the conductivity values via a certain conversion
factor. TDS and conductivity is linear related, and its conversion factor is 0.40 to 1.00. Adjust the
factor in parameter setting P5 based on the requirements in different industries. The factory default
setting is 0.71.
d) Salinity and conductivity is linear related, and its conversion factor is 0.5.
e) Once conductivity is calibrated, TDS, salinity, and resistivtiy will be automatically calibrated.
f) Conversion Example: if conductivity measurement is 1000µS/cm, then the default TDS measurement
will be 710 ppm (under the default 0.71 conversion factor), and the salinity be 0.5 ppt. If TDS
conversion rate is changed to 0.5, then the TDS measurement will be 500 ppm.
7.3 Temperature compensation factor
The default setting of the temp. compensation factor is 2.0%/˚C. You can adjust the factor based
on test solution and experimental data in parameter setting P4. The following table is some
common examples for setting up the temp. compensation factor.
Solution
NaCl
5% NaOH
Dilute ammonia
Calibration Standards
12.88 mS
Temperature
compensation factor
2.12%/˚C
1.72%/˚C
1.88%/˚C
- 7 -
84 μS
1413 μS
comes up and stays). Press
Solution
10% Hydrochloric acid
5% Sulfuric acid
Measuring Range
0 - 200 μS
200 - 2000 μS
2 - 20 mS (2000 - 20,000 µS)
Temperature
compensation factor
1.32%/˚C
0.96%/˚C
to switch