YOKOGAWA PH71, User Manual

Page: 55 / 100

IM 12B03D01-01E
6-6
6. Maintenance
6.7 Storage and O-ring/Gasket Replacement
• Storage Precautions
Care is required when storing the meter and sensor. To maintain in good condition,
observe the following:
(1) Before storage, wash off remaining sample solution from the sensor with water.
Deposits on the liquid junction, if any, must be removed thoroughly, or the
junction may be clogged. A clogged junction will cause invalid measurements,
e.g., unstable pH readings.
Keep a wetting cap attached to the sensor. For KCl refillable type sensors, seal the
fill hole with a plug.
(2) Leave the sensor connected to the meter body to protect the connectors and O-ring
from staining. Contamination may cause deteriorated insulation of connectors or
poor water resistance by the O-ring.
(3) Do not place any object on top of the sensor or on the top of the PH71 meter.
F0604.EPS
Wetting cap
Protective cover
Attach wetting cap containing cotton
wad moistened with a few drops of
water.
For KCl refillable type sensor,
seal fill hole with plug.
Figure 6.4 Sensor Storage Condition
• Storage Location
When not in use, store the meter and sensor in a safe place. If it is to be stored for a long
period, store it in a place:
• With low humidity at or near normal temperatures
• Not exposed to direct sunlight or water
• No corrosive gases are present
• Replacing the O-ring and Gasket
A gasket in the battery box and an O-ring on the sensor connector of the meter can be
replaced. Heavily contaminated or damaged gasket and/or O-ring should be replaced.
CAUTION
When installing an O-ring and gasket, clean them and their mounting surfaces with a
cloth moistened with alcohol so that they are free from dirt. Otherwise, water resistance
may not be assured.