YOKOGAWA UV700G, User Manual

Page: 106 / 131

<8. Maintenance>
8-11
IM 12K01B02-01E
8.3 Cleaning of Sampling Unit
Here describes the cleaning method of the sampling unit.
Perform cleaning periodically to remove contamination and sludge etc.
8.3.1 Cleaning of Overflow Tank and Measuring Tank
1. Turn ON the maintenance switch of the converter and stop the supply of sample water.
2. Turn OFF the power switch.
Open the lid of overflow tank. Remove the detector from the measuring tank.
CAUTION
When removing the detector from the measuring tank, take care not to damage the cell unit. In
addition, put the detector on the calibration tank with solution (sample water or tap water) so that
it does not idle.
3. Set the values, (V-1), (V-2), and (V-3) which are on the lower part of overflow tank, and the
valve (V-4) on the lower part of measuring tank to fully open. If the supply of sample water
cannot be stopped, set the valve (V-1) to close and clean all except V-1.
Refer to “Appendix 3 Piping Flow Chart”
4. Remove the inner tank of measuring tank.
Refer to “8.3.2 Removal of Inner Tank of Measuring Tank”
5. Remove the sludge from the overflow tank and measuring tank, and clean the inside with
tap water etc. If the flow from the overflow tank to measuring tank is partially clogged,
remove the piping of measuring tank and clean the inside of piping with tap water.
6. After cleaning the overflow tank, measuring tank, inner tank of measuring tank, and piping,
set back to the original condition.
7. Set the valves (V-1) and (V-4) to fully close, and (V-2) and (V-3) to fully open.
8. Supply the sample water. Open valve (V-1) gradually until sample water runs out of the
overflow outlet (1) of the overflow tank. If the sample water does not run out of the overflow
outlet (1) even when the valve (V-1) is fully open, then close valve (V-2) gradually to adjust
the flow from the overflow outlet (1).
9. Ensure that sample water overflows from the 2 upper notches of the inner tank of measuring
tank and is discharged from the drain outlet.
Inner tank of measuring tank
10. When outlet flow from the overflow tank and the inner tank of measuring tank reaches the
designated volume and is running stably, put the lid of overflow tank back on.
11. If calibration is required, install the detector on the calibration tank. If not, install the detector
on the measuring tank.
12. Turn the power switch ON.
13. After calibration and installation of detector to the measuring tank, turn ON the maintenance
switch when the measurement is stable.