Hanna Instruments HI 9910 - Manual (Page 19)

19
SET
READ
8.00
All controllers provide for a visual dosing status
through an LED. With HI 9910 and HI 9920 the
DOSING LED lights up when the controller is in the
pH or ORP dosage mode and the terminals are
activated.
Likewise, HI 9911 provides for two LED’s, one for
ACID and another for ALK (alkaline) dosage when
the appropriate terminals are activated.
NORMAL OPERATION and NORMAL OPERATION and NORMAL OPERATION and NORMAL OPERATION and NORMAL OPERATION and
MEASUREMENT MEASUREMENT MEASUREMENT MEASUREMENT MEASUREMENT
ATC MTC
ATC MTC
MTC
°C
-10 80
10
0
30
20
60
70
40
50
DOSING
ACID
FEED
ALK
Make sure that the controller has been properly calibrated before
commencing and that the pH or ORP setpoint(s) have been adjusted
(see the following pages).
The pH or ORP electrodes and any ground probes must be properly
connected and wired to the controller (see preceding pages). Remove
the protecteive cap if it is still on the tip of the electrode.
Ensure that the electrode is properly installed and lies perma-
nently in the solution to a depth of at least 4cm/1.5”. The
selector (see 7 - Functional Diagram) must be on the "READ"
position.
If temperature compensation is necessary (HI 9910 and HI 9911),
make sure that the temperature probe is also immersed in the
solution and the selector is on ATC (see 17 - Functional Diagram).
For manual temperature compensation, the se-
lector should be on MTC with the dial showing
the temperature of the solution.
The actual pH or ORP value of the solution will be displayed on the
LCD.
SET
READ