Performing 1-Point Calibration; Performing Multi-Point Calibration; Ph Measurement - OHAUS ST400 Manuel D'instructions

EN-14
3.3.2

Performing 1-point calibration

Place the pH electrode in the buffer, and press
and continue to press
"calibrating" is displayed at the bottom of the screen, and the
screen. After the first calibration point complete, "press the calibration button to continue
calibration" will be displayed at the bottom of the screen. The corresponding calibration buffer is
displayed and stored.
The 1-point calibration is finished. There are now 2 options (OHAUS recommends conducting at
least a 2-point calibration);
1. When performing calibration, Ohaus recommends using Auto End Point Mode.
Press button-
2. Press button-
shown on the top right corner of the screen then return to the measurement screen.
Note: With the 1-point calibration, only the offset is adjusted. If the sensor was previously
calibrated with multi-point calibration, the stored slope will remain. Otherwise theoretical 100%
slope (-59.16 mV / pH) will be used.
3.4

Performing Multi-point calibration


Perform 1-point calibration as described above.

Rinse the pH electrode with pure water.

Place the electrode in the next calibration buffer, stir and wait for a few seconds, then press
button-
The meter reaches the calibration endpoint with the result display on the screen. The 2 point
calibration is finished. Then you can continue to do the 3-point calibration, 4-point calibration and
5-point calibration, or stop the calibration.
Note: If the electrode calibration fails, "calibration error" will be displayed at the bottom of the
screen, and the calibration results are not saved.
3.5

pH measurement

3.5.1 pH measurement

Calibrate and make sure the electrode is in good condition, then start pH measurement.

Place the electrode in the sample, stir and wait several seconds.
button to start calibration. During the calibration, the
to continue calibration.
to complete the calibration, the offset and the slope are
, "Calibrating" displays on the bottom of the screen.
ST400 & ST400M Portable Meter
button to enter the calibration mode,
is displayed at the top of the