Ph Measurements - Radiometer Analytical MeterLab PHM220 Mode D'emploi

pH Measurements

pH measurements can be performed in three ways:
• Manually with a live pH reading on the display.
• Using the AUTOREAD function which locks the pH result on the
display as soon as the signal is stable. Stability is defined by the
stability criterion set in Edit SAMPLE.
• AT INTERVALS; sample pH is measured continuously and
printed out at specific time intervals.
1. A reliable pH measurement requires a current set of calibration
data (zero pH and sensitivity). You should either perform a new
one or two-point calibration or check when the last calibration was
made by pressing the GLP key and selecting CAL.
2. Press the Mode key and select pH using the left or right arrow
key.
3. Rinse the electrode(s) and temperature sensor thoroughly with
deionised water and dab dry with soft tissue.
4. Immerse the electrode(s) and temperature sensor in the sample
and apply proper stirring.
5. Press the pH/mV key to initiate sample measurements.
6. If a temperature sensor is connected, the actual pH value and
temperature measured will be displayed. If no temperature sensor
is used, the actual measuring temperature should now be adjusted
using the arrow keys.
Without a temperature sensor
STAB STAB
pH
7. Read the pH value when the signal becomes stable, i.e. when the
stability indicator displays "STAB" continuously. When "STAB" is
displayed, it means that the stability criterion is reached. The
letters " ", "S", "ST", "STA" appear as stabilisation progresses.
Manual pH Measurements
7.00pH
26 ˚C
With a temperature sensor
STAB STAB 7.00pH
pH 21.3˚C
Starting up
21