All pH circuits require a high
impedance pre-amp to which the electrode connects.
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This pre-amp will either be
a part of the the meter or is available as a separate external
component. Many process controllers require external
preamplifiers, to match the impedance gain of the electronic circuit
to the actual pH electrode.
PRODUCT FEATURES
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Sensorex electrodes can be connected directly
to the meter, when the pre-amp is built into the circuit, and the
cables are relatively short.
For longer cable runs (more than about 22 feet
or about 7 meters) or where there is significant plant electrical
"noise", an external preamplifier will help to provide a cleaner
signal. You may even be able to obtain longer life from your
pH electrodes!
When the Original Equipment Pre-amp
cannot be accessed; (for example, it may be built into a disposable
electrode), a Sensorex Pre-amp will be needed, regardless of the
length of cable.
Low cost battery powered inline preamplifiers such as our PHAMP-1
may be adequate to match up to your controller. The economical
Sensorex PHAMP-1 is a battery powered in-line design. It is
designed to boost the signal and lower the impedance from a pH
electrode to a pH monitor, controller or transmitter. It can
be used for long cable runs of up to 1,200 feet (300 meters).
Use this pre-amp when your instrument is not designed to power a
remote amplifier. The PHAMP-1 can also be used to input a pH
electrode signal directly into a device which can accept voltage
inputs. The batteries are sealed, and have an estimated
life of more than 3 years. The PHAMP-1 has an operational output of
+/- 2000 mV. The BNC connector from your coax electrode cable is
attached to the BNC Receptacle input connection on the
PHAMP-1. The output is a BNC connector. You must have a
BNR receptacle on your Cable to connect from the output and go to
your controller. Sensorex provides accessory cables and
adapters to make this transition. The PHAMP-1 is not water
proof, you must protect it from water and the elements.
OEM line powered
preamplifiers are more economical over the long term, and provide
the optimum service life for the majority of installations. Refer to
the Preamplifier Guide (below) to select the Pre-amp Locate the
Original Equipment meter in Column A and order the Pre-amp listed in
Column B. Download pre-amp
wiring diagrams.
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PREAMPLIFIER GUIDE |
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Meter-Transmitter-Controller
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Preamplifier |
Great Lakes, 670 300 |
Preamplifier |
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All controllers not pre-amp ready |
PHAMP-1 |
L & N, 7073, 7075 , 7082, 7083, 7084 |
PHAMP-1 |
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Beckman, SoluComp |
U698-03 |
L & N, 7076, 7079 |
U698-03 |
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Beckman, 940
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V-1 |
Lakewood 820,830, |
V-1 |
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Beckman, 960 |
V-2 |
Rosemount/Uniloc, 1000, 1001, 1002, 1003 |
V-2 |
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Foxboro, 2220 |
V-1 |
Rosemount/Uniloc, 1050, 1181 |
V-1 |
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Foxboro, 870, 872, 873, 874 |
V-2 |
Rosemount, 1054, 1054A, SoluComp |
V-2 |
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Great Lakes, 60, 70 |
V-1 |
Rosemount 2081 |
V-1 |
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Great Lakes, 90, 95, 570, 671, 672, 690 300 |
GL90-A |
Signet 710, 719, 750, 9750, 9759, 9030 |
GL90-A |
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How to
Order