Aquametrix P/R60 Differential pH/ORP Sensors Datasheet - Manual

AquaMetrix pH and ORP differential
probes stay in service and provide accu-
rate measurements under conditions that
often render conventional pH probes in-
operable. Now for added versatility, these
probes, field-proven in hundreds of instal-
lations, are available with an integral en-
capsulated 4-20 mA two-wire transmitter
to feed directly to a PLC or a DCS.
The P65 pH and R65 ORP probes em-
ploy a differential measurement tech-
nique. Unlike conventional combination
probes, the differential probe has two
high impedance measurement circuits
containing a common metallic return
electrode. One circuit includes the pro-
cess measurement electrode which gen-
erates a potential E1 proportional to the
process pH. The second circuit includes
an internal measurement electrode im-
mersed in a stable buffer solution which
generates a standard reference potential,
E2. Both circuitshave a common potential
E3 developed at the return electrode. The
two circuits are fed into amplifiers which
provide an output representing the differ-
ential between them:
(E1 - E 3) - (E2 - E3). The common po-
tential E3 is cancelled out electronically,
greatly reducing inaccuracies caused by
ground loops which may exist between
process and instrument grounds. Ground
loop current willflow through the low im-
pedance path of the return electrode, af-
fecting the potential E3, but not the dif-
ferential measurement.
The differential probe maintains its accu-
racy and stability in aggressive process
applications long after a combination-
style probe’s performance begins to de-
teriorate.
Maintenance costs are reduced and the
life of the probe is increased. The internal
reference electrode is electrically con-
nected to the process solution by means
of a field-replaceable double junction salt
bridge which greatly reduces the possibil-
ity of contamination of the buffer solution
in the reference circuit. Although seldom
required, the reference solution may be
easily replaced by removing the screw-
out salt bridge. A salt bridge and buffer kit
is available for this purpose.
Another advantage of the 65 series is the
semi-flush face which is easily cleaned
and avoids solution materials gather-
ing on protrusions found in competitive
probes. The domed glass electrode, the
protective metal electrode and the tem-
perature sensor protrude only about 1/8
inch while the salt bridge is flush. A flat-
face version of the pH probe is also avail-
able.
The 65 series can be provided in any of
the physical configurations in the P60/
R60 series differential probes: 65C-8
with 1-1/2” threaded body style, 65C-6
“Easy-In, Easy-Out” variable insertion
depth version with 1- 1/4” NPT compres-
sion fitting, or the 65C-7 hot tap version.
Two-Wire Transmitter built in
• Integral two-wire 4-20
mA transmitter can be fed
directly to PLC, DCS
Differential Measurement
• Replaceable Salt Bridge
• Long-lasting
• Low Maintenance Cost
• Field-proven
• Reduces ground loop problems
Easy Cleaning
• • Semi-flush face: re-
duced buildup
Temperature Compensation
• Automatic temperature compen-
sation on pH versions
Options
• Flow-through and submersion
• Hot-Tap available
• Flat-faced available (pH)
• Gold electrode available (ORP)
• Differential pH & ORP ver-
sions without 2 wire transmitter
available (see P/R60 series)
Aquametrix Model P65C/R65C
Probes with 4 to 20 mA Output
by
Water Analytics
AquaMetrix
100 School Street
Andover, MA 01810
978-749-9949
Toll free - 855-747-7623
www.WaterAnalytics.net
• Process Control
• Industrial and Municipal Wa-
ter Treatment
• Industrial and Municipal
Waste Treatment and Neutral-
ization
• Fume Scrubbers, Plating,
Circuit Board Manufacturing,
Food and Beverage, Chemi-
cal Processing, Pulp and Pa-
per, Mining, Power Generation,
Pharmaceutical Industry
Description
Features
Applications
by
Water Analytics
AquaMetrix