YOKOGAWA Vigilant Plant EXA TB Series, User Manual

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<7. MAINTENANCE>
7-8
IM 12E04A02-02E
NOTE
• Avoid rubbing the surface with any material.
• For cleaning, do not use agents other than a detergent (e.g., a solvent such as ethanol,
acetone, etc.).
• For cleaning, also avoid touching the surface with your fi ngers.
• If the surface gets scratched, a correct turbidity reading cannot be obtained. Be sure to
exercise care in handling.
7.7.2 Span Calibration Using Standard Solution
Span calibration is carried out normally with the calibration plate. However, if the standard
solution is to be used, do it in the following procedure.
1. Prepare 10 liters or more of the standard solution (see Subsection 7.15.2).
2. Select FUNCTION "D." in the <PROGRAM1> mode and change the setting to "OFF".
"OFF" means calibration with the standard solution ("ON" is set upon shipment from the
factory).
3. Select FUNCTION "4" in the <MAINT.> mode. => "Turbidity value" is displayed.
4. Stop supplying the measuring water and once drain the measuring water into the detector.
5. Drain several times using "zero water" and remove the dirt on the detector and header tank.
Finally, stop the "zero water" and drain off the detector and the header tank so that no water
remains in them.
6. Connect the standard solution tank to the measuring water feed inlet and supply the
standard solution at 2 l/min using a pump. Supply the standard solution agitating it with a
magnetic stirrer.
7. When the standard solution begins to over fl ow the measuring cell, stop supplying the
standard solution by turning off the pump, and drain it off by opening the drain value. Then
close the drain valve and again supply the standard solution.
8. Allow the standard solution to fl ow for 4 minutes or more and after the reading stabilizes,
carry out span calibration. For the operating procedure, see Section 6.5 (4).
9. After calibration is completed, stop supplying the standard solution and drain it.
Reconnect the measuring water piping and restart the supply of measuring water. It takes a
certain time until the detector, heater tank, and piping are completely fi lled new measuring
water.
10. Select FUNCTION "D." in the <PROGRAM1> mode and return the setting to "ON".
11. Finished.
3rd Edition : May. 31, 2010-00