YOKOGAWA PH72, Руководство пользователя

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IM 12B03D02-01E
2-4
2 . Preparation
2.5 Wetting Cap
The glass electrode should be kept wet during storage. If the glass electrode dries
out, it will take hours to rehydrate and in the meantime the meter may give erroneous
readings. The wetting cap is used to prevent the glass electrode from drying out.
Sensors are shipped with a wetting cap containing a cotton wad moistened with a few
drops of water. For storage replenish the cap with a few drops of water (tap water)
and attach to the sensor firmly.
F0201.ai
Protective cover
Lug
Slot
To remove cap, rotate counterclockwise
and pull out until lugs on cap clear
protective cover through slots.
Removed cap can be
attached onto sensor cable
during measurement.
Figure 2.1 Wetting Cap
2.6 Manual Temperature Setting
If a sensor without a built-in temperature element (needle type or test tube size pH
sensor) is connected to the meter, mark will appear on the display. In this
case, measure the temperature of the solution being measured and manually set the
measured temperature into the PH72 meter for reliable measurement. The procedure
is described in Section 5.3 (2), “Manual temperature setting (M.tP) panel.”
Temperature compensation is performed based on a temperature shown on the
display of the PH72 meter. If a temperature shown on the display is different from the
actual temperature of the sample being measured, the displayed measured value
may not be true. The bigger the difference between the temperature displayed on the
meter and the actual temperature of the solution, the bigger the error between the
displayed measured value and the true value.
If mark appears on the display even though a sensor with a built-in
temperature element is connected, refer to Section 7.4.
2.7 pH Calibration
The PH72 meter needs to be calibrated:
• when the sensor is connected for the first time;
• after the sensor is replaced;
• after the meter has been stored for a long period;
• after the electrode is cleaned; or
• when necessary.
The calibration procedure is described in Chapter 4, “Calibration.”
Note: Calibration results are saved in the meter when the batteries are replaced.