Conductivity Calibration; Conductivity Measuring; Tds, Salinity And Resistivity Measuring - OHAUS ST400 Manuel D'instructions

EN-16
to select between five conductivity buffers. press
button to return to the measuring mode or continue to set other parameters. The
predefined standard buffers of the meter are 10 μS/cm, 84 μS/cm, 500 μS/cm, 1413 μS/cm and
12.88 mS/cm, and the actual conductivity of different temperature is built-in in the meter program.
3.6.2

Conductivity calibration

After selecting the conductivity standard buffer, you can start to calibrate.

First, make sure that the meter and the conductivity electrode are connected, and the
conductivity electrode is rinsed with pure water and dried.

Place the conductivity electrode in the corresponding standard buffer, press
button to start calibration.
After reaching and locking the end-point (automatic end-point or manual end-point), the meter
displays the calibration value and electrode constant and temperature compensation coefficient in
the upper right corner of the screen.
Note: In order to ensure accurate conductivity reading, the electrode should be calibrated
regularly with standard buffer. Please use the standard buffer within the period of validity.
Wrong calibration operation in air: if the conductivity electrode is connected to the meter, press
the calibration when the electrode is in the air, then the meter will always show "---", sometimes
there is an error message, indicating that the value is out of range. For example, STCON3, the
normal electrode constant should be between 1.50 and 2.00 /cm. If the calibration is conducted in
the air, the electrode constant will be abnormal, for example, it displays 1320 /cm. In this case, the
electrode can be recalibrated in the standard buffer.
3.6.3

Conductivity measuring

The section only applies to ST400M.
Do not measure when connecting to the computer or charger.
Please confirm that the conductivity electrode is properly connected, and the conductivity
electrode is rinsed with pure water and dried. Place the conductivity electrode in the sample, press
to start measuring.
The measured results can be obtained under the automatic or manual end-point mode. If the
repeatability is poor in the automatic end-point mode, it is suggested to use the manual end-point
mode.
Note:
The sample measurement result is automatically compensated to the reference temperature (20
or 25 ° C) according to the measured temperature and temperature compensation coefficient
(alpha value).
3.6.4

TDS, Salinity and resistivity measuring

To measure TDS (total dissolved solid) or salinity, please follow the same steps as the
ST400 & ST400M Portable Meter
button to confirm setting. Then press