Maintenance - Hach AF7000 Basic User Manual

Adjust the zero point
The zero point can be changed to increase or decrease the coagulant dosage. Increase the zero
point setting to decrease the coagulant dose. Decrease the zero point setting to increase the
coagulant dose.
1. Put the controller in manual mode.
2. Push and hold the Up or Down key for two seconds.
3. Push the Up or Down key to increase or decrease the zero point setting (top display).
4. Put the controller in automatic mode. The coagulant dose changes until the zero point setting
shows 0.

Maintenance

Multiple hazards. Only qualified personnel must conduct the tasks described in this section of the
document.
Maintenance schedule
Table 4 shows the recommended schedule of maintenance tasks. Facility requirements and
operating conditions may increase the frequency of some tasks.
Task
Examine and clean the sensor. Refer to
Clean the sensor on page 17.
Examine the replaceable parts for wear.
Refer to Examine the replaceable parts
on page 18.
2
Replace the piston.
Replace the cam rod to piston linkage.
Replace the linear bearings.
2
Replace the sensor.
1
Do this task also after each high-turbidity event.
2
Refer to the instructions that are supplied with the replacement part.
Clean spills
Chemical exposure hazard. Dispose of chemicals and wastes in accordance with local, regional and
national regulations.
1. Obey all facility safety protocols for spill control.
2. Discard the waste according to applicable regulations.
Clean the instrument
Clean the exterior of the instrument with a moist cloth and a mild soap solution and then wipe the
instrument dry.
16 English
D A N G E R
Table 4 Maintenance schedule
14 days
1
X (without auto-
flush)
2
2
C A U T I O N
1 month 6 months 1 year 5 years
1
X (with grit filter
and auto-flush)
X
X
X
X
X