| Disposal Assembly |
The
disposal assembly composes of a disposal tank with level switch, a diaphragm
pump (item P3) and solenoid valves (item V3 and V4). A conductivity level
switch (item LSD) with three electrodes (item LD1, LD2 and LD3) is also installed
in the cover of the disposal tank, and is used to control the level of the
disposal tank in two setting points. All the inlets coupled to the disposal
tank are connected 
to
a manifold first, and then only one pipe is coupled to the cover of the disposal
tank directly. All the chemical solutions used in the analysis chambers, including
the MF chamber, the ISE chamber and the HM chamber, are drained to the disposal
tank finally. When the level of the disposal tank reach the high predetermined
point (item LD1), the control system will activate pump P3 to transport the
waste solution back to treatment tanks. When the level of the disposal tank
is below the low predetermined point (item LD2), the control system will stop
pump P3. Solenoid valves V3 and V4 are interlocked and used to select which
treatment tank waste solution returns back to.
