Yokogawa PH72 Personal pH/ORP Meter - Manual (Page 25)

IM 12B03D02-01E 3-2
3. Measurement
3.2 Measurement Procedures
Immersing the sensor
Immerse the sensor so that the protective cover part goes under the sample solution level.
The sensor does not need to be immersed deeply.
When using a KCl refillable type sensor, the filling solution level must be above the
level of solution being measured. This is to prevent the KCl filling solution from being
mixed with the sample solution.
F0302.EPS
Level of filling solution
(refill when level is low)
Fill hole
(left open during measurement)
Protective cover Sample solution
Level of sample solution
KCl refillable type sensor must be immersed so filling
solution level is above the level of sample solution.
Figure 3.2 How to Immerse the KCl Refillable Type Sensor
Bubbles trapped in the glass electrode tip may interfere with accurate measurement.
Before taking measurements, check the electrode tip for bubbles. If present, gently shake
the sensor, as shown in Figure 3.3, to dislodge bubbles from the tip.
Bubbles
Enlarged View of A
A
Filling solution
Filling solution
Glass electrode tip
* No bubbles
allowed in tip.
F0303.EPS
Figure 3.3 How to Dislodge Bubbles from Glass Electrode Tip