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Features
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Guaranteed Longest Lasting
Sensors Available with performance guarantee *
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Sensors are compatible with most
existing pH/ORP Meters, Transmitters & Analyzers **
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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. 1 –
Ammonium Nitrate Manufacturing
Ammonium Nitrate Fertilizer
Manufacturer - High Temperature Inline Environments
Strong Acid/Fluoride Resistant pH
Element & High Temperature and Acid/Fluoride Resistant Solid State Reference
Junction.
Chemically & Thermally Resistant
ULTEM & PEEK plastic body housings
Application Oriented Engineering
and Custom Built to Order sensor increased the lifetime by Two to Five
Fold
The Problem
An
ammonium nitrate fertilizer manufacturer was lacking a pH sensor that offered
accurate measurement in high-temperature inline acid and ammonia environments,
resulting in under reacted chemicals with lower production yields. The
extreme process conditions resulted in limited lifetime for the sensor; which
rarely exceeded days or weeks in the reactor and only functioned for up to a
month in a specially constructed heat-reducing
bypass system. To circumvent this
problem, the manufacturer had to cool the sample by diluting it 1:1 with
water via the heat-reducing bypass system. This action solved the temperature problem, but decreased the accuracy
of the measurement making it dependent on the 1:1 sample to water ratio
measurement. The signal also was delayed because of the addition of the bypass
line. If the reaction was running on the ammonia excess side, the ammonia gas
entered the sensor and destroyed the secondary reference half cell, thus suddenly
and significantly reducing the operational lifetime of the sensor. If the process
was allowed to run on the nitric acid excess side, the result was under
reacted ammonia gas and rapid aging of the pH element.
The Solution
The
combination of a high temperature and acid resistant pH element (with a
protective seal against the ammonia gas) in conjunction with a high
temperature and acid resistant solid state junction was able to facilitate
all the measurement needs of this application. This system was encased within
an acid resistant ¾”–1” MNPT ULTEM or PEEK thermoplastic sensor body housing.
This permitted the manufacturer to place the sensor into the wall of the
reactor and obtain real time pH readings thereby increasing the yield of
their production. The improved design increased the lifetime of the sensor by
approximately four times over the previously used sensor, despite the
increase in the temperature and chemical exposure. The appropriate
electronic components were integrated into each pH sensor to retrofit
directly with the available pH transmitters.
The Ultra-High
Temperature rated pH Sensor Used:
Model: PNA 6241/6441-873-10 Inline pH Sensor (Rated to 150
ºC at 150 psi)
Description: ¾”- 1” MNPT
Immersion PEEK Bodied Ultra High Temperature, Dissolved Gas and Acid/Fluoride
Resistant pH Sensor; Integrated 100 Ohm Platinum Temperature Element, Stainless
Steel Solution Ground & Foxboro compatible 873 preamplifier; 10 feet
cable to connect directly to Foxboro 873 pH Analyzer/Transmitter
The High Temperature rated
pH Sensor Used:
Model: PNA 6131/6431-1181-10 Inline pH Sensor (Rated to
135 ºC at 100 psi)
Description: ¾”- 1” MNPT
Immersion ULTEM Bodied High Temperature, Dissolved Gas and Acid/Fluoride
Resistant pH Sensor; Integrated 3000 Ohm Balco Temperature Compensator & Uniloc-Rosemount
compatible 1181 preamplifier; 10 feet cable to connect directly to Uniloc-Rosemount
1181 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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