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March 2020
1
Description and specifications
1.1
Features and applications
The ion-selective field effect transistor (ISFET) pH electrode provides a stable
pH measurement.
Its rate of response can be ten times faster than glass electrodes, enabling
better process control. Its short response time and increased stability at low
temperatures makes it suitable for use in cold processes like brine or water
for cooling. Aging effects caused by temperature fluctuations or large
changes of process pH are greatly reduced, providing longer intervals
between calibration and maintenance of the sensor.
Because there is no glass bulb, you can use the sensor in many applications
that restrict or prohibit pH glass electrodes due to the risk of broken glass
getting into the process. It may also provide longer sensor life in processes
that will break or crack pH glass bulbs. By allowing direct installation into the
process, costs for laboratory analysis of sample lines are greatly reduced.
The TUpH Reference technology includes a large area reference junction for
minimum maintenance requirements. The reference junction provides an
electrical connection between the reference electrode and the sample and
helps maintain a stable reference potential, regardless of the change in
sample pH. The TUpH reference electrode junction (the entire plastic tip
surrounding the ISFET electrode) maintains a steady reference signal, even
in dirty applications, by resisting plugging (a common cause of pH signal
drift). This large reference junction area (400 times greater than typical PTFE
or ceramic junctions) is made of micron-sized reference pathways, allowing
for ionic exchange, but preventing plugging by larger particles; the junction
continues to send a pH signal even in the dirtiest of applications. The field-
proven TUpH reference junction technology results in greatly reduced
maintenance requirements.
The TUpH helical reference pathway resists reference poisoning. Ions diffuse
through the reference pathways, and a charge is passed to the reference
element. The reference element must be protected from contamination by
poisoning ions such as sulfide, mercury, cyanide, and ammonia that will
cause reference drifts and offsets. The TUpH sensor's long internal reference
pathway hinders the contaminants' migration to the reference element
thereby providing an increased sensor life.
Emerson has specifically designed all TUpH sensor models for improved
performance in harsh, dirty, or abrasive applications where large quantities
or suspended solids are present.
The Rosemount TF396 offers a watertight sensor-to-cable connector that
prevents cable twisting and eliminates the need for rewiring when replacing
the sensor. The sensor cable includes an integral preamplifier cap with
mating connector and is compatible with most Rosemount transmitters.
Quick Start Guide
Quick Start Guide
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