YOKOGAWA PH450G

<6. Troubleshooting>
6-1
IM 12B07W01-04EN 1st Edition : Nov. 11, 2016-00
6. Troubleshooting
This chapter deals with the corrective actions taken when the system fails to operate normally
due to, for example, a failure in components. For malfunctions regarding the PH450G pH/
ORP Converter or FLXA202/FLXA21 2-Wire Analyzer and PH8EFP pH sensor, refer to the
correspondng user’s manual supplied with these instruments.
6.1 More Than 100 ml of Chemical Solution at a
Time Is Being Fed to Holder
The primary reason is that air may be leaking from the O-ring in the metering tank. Since an
excessive air leak allows the chemical solution to enter the metering tank up to the level of the
surface of the liquid in the holding tank, more than the required quantity (approximately 100 ml) of
the chemical solution is supplied.
l Corrective action
Tighten the cap fully. If the air leak still persists, check the cylinder barrel for possible cracks and
the O-ring for possible defects. Replace defective components, if necessary.
Cap
O-ring
Pneumatic
pressurizing tube
Tube for
forced feeding
Gasket
Bleed valve
Level of liquid
in holding tank
Level of liquid in metering tank
(capacity: approximately 100 ml)
Fluid inlet
Metering tank
Holding tank for chemical solution
Check
Valve
(Seat)
Figure 6.1 Normal Level of Liquid in Metering Tank
If the holding tank is positioned below the cleaning chamber of the holder conrm that at least a
part of the tubing is positioned above the cleaning chamber. Failure to observe this instruction
may result in the chemical solution fed to the cleaning chamber owing back into the holding tank
after the air bubbling.
Note: If the chemical solution in the cleaning chamber ows back into the holding tank, clean
the bleed valve to prevent it from being clogged.