3
8860 Dual Channel Conductivity/Resistivity Controller
Sensor Input Connections
• The 8860 will accept two independent sensor input signals.
The two sensors may be of different cell constant values.
• Do not route sensor cable in any conduit containing AC power
wiring - electrical noise may interfere with the signal.
• Cable shield MUST be maintained through cable splice.
• Use three conductor shielded cable for cable extensions up
to 30 m (100 ft) max. for measurements below 10 M
Ω
(above
0.10
μ
S).
• Maximum cable length for resistivity measurements above
10
M
Ω
is 25 ft, and solution temperatures must be between
20°C and 100°C.
Relay and Open Collector Functions
The 8860 is equipped with 4 SPDT relays that can be con
fi
gured
for High alarm, Low alarm, Proportional pulse or USP operation.
•
Low:
Output triggers when process variable is less than
setpoint.
•
High:
Output triggers when process variable is higher than
setpoint.
•
Off:
Disables output pulse.
• Pulse
Operation
The output emits a 100 mS pulse at a rate de
fi
ned by the
Source, Pulse Range and Max PlsRate settings, and by the
process condition. The maximum pulse rate is 400 pulses per
minute.
Example: As the process falls below 10
μ
S the output will
start pulsing in relation to the process value, the max pulse
endpoint and the programmed pulses/min. Pulse rate
will increase as the process approaches the programmed
endpoint.
SHLD
ISO GND
TEMP
2
SGNL
2
SHLD
ISO GND
TEMP
1
SGNL
1
RED
WHITE
BLACK
SILVER (SHLD)
RED
WHITE
BLACK
SILVER (SHLD)
Hysteresis
Time
Low Setpoint
Process
Relay energized
Relay relaxed
Hysteresis
Time
High Setpoint
Process
10
5
Relay 1 Rng: μS
10.00 --> 5.00 >
Relay/Open Collector PlsRate:
100 Pulses/min >
10 μS
= 0 pulses/min.
7.5 μS = 50 pulses/min.
5 μS
= 100 pulses/min.
RANGE defines where the pulsing starts
and where it reaches the maximum rate.
Pulse rate
µS ----->
0 pulses
100 pulses
The Pulse Rate determines what the
maximum rate will be. The 8860 maximum
capability is 400 pulses per minute.
1μS
1MΩ
10μS
100KΩ
1,000μS
10,000μS
50,000μS
200,000μS
100μS
10KΩ
400,000μS
100,000μS
0.054μS
18.3 MΩ
Bottled
Water
Brackish Sea Water
(Salinity)
UPW @ 25°C
USP
Cooling Tower
Waste Waters
Deionization Regen. Chemicals
Alkali Cleaners, Acids/Bases
Rinse
Water
3-2819, 3-2839
(0.01 Cell)
3-2820, 3-2840
( 0.10 Cell)
3-2821, 3-2841
(1.0 Cell)
3-2822, 3-2842
(10.0 Cell)
3-2823
(20.0 Cell)
0.010μS
100 MΩ
200μS