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Features
·
Guaranteed Longest Lasting
Sensors Available with performance guarantee *
·
Sensors are compatible with most
existing pH/ORP Meters, Transmitters & Analyzers **
·
Application Specific Engineering
results in optimum Lifetime & Performance ***
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Integrated Temperature
Compensation, Preamplifiers & Solution Ground Elements
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Solid State Reference System offers superior resistance to Fouling
& Dehydration
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Applications such as Acid/Fluoride,
Hi-Temp, Saturated Sodium and Sulfide Resistant are available as standard
options
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Custom Applications are available,
often at no additional charge
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Most Installation Styles are
Supported Including: Immersion, Twist Lock, Valve Retractable
& Sanitary
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Available in a wide range of plastics,
from cost effective CPVC to thermally & chemically resilient ULTEM®
and PEEK thermoplastic
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High Pressure Applications up to
100 psi for Valve Retractable & 150 psi for Inline Installations can be
supported for continuous use
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Operating Temperatures from -30
to +150 ºC (-22 to +302 ºF) can be supported
for continuous use
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Case Study No. 4 – pH
in Organic Solvent Recovery Systems
pH measurement in almost
pure (99%) Organic Solvents & Solvent Recovery Systems
Specialized Organic Solvent
Resistant Solid State Reference System
Wide Range pH element to handle wild pH fluctuations in small
water phase of process (1% water total)
Extremely high chemical
resistance offered by PEEK sensor body housing
Integrated high temperature
rated temperature compensation elements, stainless steel solution ground, and
high impedance CMOS operational amplifiers (preamplifiers) that allow
retrofitting to almost any existing pH transmitter
Proven Solution for pH
measurement in Class I, Division I (Zone 0) Areas
The Problem
A
manufacturer of organic chemicals required process control equipment for its
solvent recovery system. This process consisted of the collection of the used
solvents and the storage of a mixture consisting of fractional distillations.
The solvents accumulated some water during the process, this water extracted
acids or alkali from the product and was carried into the storage tank. Since
there was only a small amount of water, the concentration of the resulting acids
and alkali was very high. In some cases, the small percentage of water was
so corrosive that the stainless steel tank was attacked and the solvents
leaked into the atmosphere. Repeated attempts to measure the pH value failed
because the solvent mixture either dissolved the sensor or attacked the
reference junction making it inoperable. The rapid and sometimes
unpredictable fluctuations in pH made accurate readings difficult. Due to
electrical consideration and area classification rules, an integrated
preamplifier was required to get stable usable potentials from the pH sensor.
The Solution
What
was required was a sensor that was constructed of components that are
impervious to the wide variety of process chemicals employed. This was
accomplished by use of a wide range thick wall pH glass element, a solvent media
resistant solid state reference junction and an immersion PEEK sensor body housing.
The necessary temperature compensator, solution ground and preamplifier where
embedded into the sensor as required for the area classification. This
custom engineered pH sensor provided a reliable, fast responding and accurate
measurement in the extreme acid and alkali environment found in the organic
solvent recovery system.
The pH Sensor Used:
Model: PNLTS 6041/6441-870IT-10 pH Sensor
Description: ¾”- 1” MNPT Immersion PEEK Bodied Organic &
Solvent Media Resistant Wide Range Acid/Fluoride Resistant pH Sensor; Integrated
1000 Ohm Platinum Temperature Element, Stainless Steel Solution Ground and
Foxboro Compatible 870IT preamplifier; 10 feet cable to connect directly to Foxboro
870IT pH Analyzer/Transmitter
Choosing the Correct pH/ORP
Sensor
1.
Choose a sensor body type that
suits the physical parameters of the
installation (refer to the Configurations
Portion of pH/ORP and Ion Selective webpages).
2. Choose
a sensor that suits the process application, temperature,
chemistry, and physical
parameters of the installation (refer to Sensor Selection Guides
and call factory or local sales agent for support)
3. Choose a sensor housing material that is compatible
with the process chemistry, temperature & pressure (refer
to Chemical Resistance Charts as posted under the Technical
Documents portion of the website).
4.
Select suitable temperature compensation element, solution
ground & integrated preamplifier based upon the mating pH/ORP Instrument (refer to Electrochemical Instrumentation
Page & ask for factory support).
5.
Specify the required
cable length based
upon installation
location (refer
to Part Numbering Guide).
*
Subject to application qualification and review by an approved ASTI sales
agent and/or factory. Performance guarantee is posted on the ASTI online
application questionnaire page.
**
See list of supported pH/ORP/ISE Instruments webpages as posted on the ASTI website.
***
Completion of Application Questionnaire form is required. Other restrictions
may apply.
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