Hanna Instruments HI 9912 - Manual (Page 10)

10
pH
0
1
2
0
100
200 mV
ALARM
pH
0 SECONDS mV 200 0 TIMER MINUTES 90 PROPORTIONAL SETTINGS 1 10
2.5 5 7.5
0 SECONDS pH 2.0 0
TIMER MINUTES 90
PROPORTIONAL SETTINGS
1 10
2.5 5 7.5
500 900 CAL ALARM ON
OFF SET
FEED
mV
OFFSET SLOPE ALARM ON
OFF 0.5 1.5
pH
HI 9912
mV
ORP
ALARM
8 SET
FEED
ALARM
6
7
ACID
OXID
700
50 150
SET pH
SET ORP
ALARM
LINE
BL DOSING
PUMPS
pH
0
1
2
0
100
200
mV
ALARM
Diagram) and remove the jumpers remove the jumpers remove the jumpers remove the jumpers remove the jumpers shorting the matching
pin terminals.
• When using a separate probe for grounding purposes, wire it to
the Matching Pin terminals on the right hand panel and
remove the jumpers
remove the jumpers remove the jumpers remove the jumpers remove the jumpers (see 14 and 15 - Functional Diagram).
NOTE:
NEVER leave the jumper in when
using an electrode with a match-
ing pin. This can shorten the life
of the electrode (reference) drasti-
cally.
ALARM CONNECTIONS
• The operator can select an alarm threshold of 0.0
to 2.0 pH and 0 to 200 mV by turning the alarm
knob (see 13 and 16 of Functional Diagram). The
alarm can be selected as normally closed ("NC") by
connecting the external device to the C and NC
terminals or normally open ("NO") by connecting
the external device to the C and NO terminals.
RELAY CONNECTIONS
• Wire the external devices (pumps or electrovalves) directly to the
relay terminal strips of the controller (see 18 and 19 - Functional
Diagram). The
terminals are
terminals are terminals are terminals are terminals are
powered
powered powered powered powered and
hence you do not
do not do not do not do not
need an ex- need an ex- need an ex- need an ex- need an ex-
ternal power
ternal power ternal power ternal power ternal power
supply
supply supply supply supply for the
pumps or valves.
NOTE:
HI 9912 provides for two separate relays, one for pH and another for
ORP. In order to save on chemicals and due to the slow reaction of
oxidants, the controller incorporates a Consent feature
Consent feature Consent feature Consent feature Consent feature by which
ORP measurements are adjusted only after pH has been corrected.
The Consent feature makes the pH correction
pH correction pH correction pH correction pH correction the master master master master master and the
ORP adjustment ORP adjustment ORP adjustment ORP adjustment ORP adjustment the salve salve salve salve salve for a better control.
REMOVE WHEN
USING MATCHING PIN