Description And Specifications; Features And Applications - Emerson Rosemount 389 Reference Manual

Reference Manual
00809-0100-3389
1

Description and Specifications

1.1

Features and applications

Rosemount 389VP triple-junction sensors are offered with SMART capabilities. SMART
options are enabled when used with Rosemount 1056, 1057, 1066, and 56 transmitters.
The pH-loop capabilities include auto-recognition of the SMART sensor, automatic upload
of calibration data and associated time stamp, and historical recording of pH diagnostics
(slope, offset, reference impedance, and glass impedance). This trending data allows
technicians to predict frequency of maintenance and estimate sensor life for a particular
process condition. Additional SMART features include factory calibration, resetting SMART
sensor calibration data with user menus without power cycling, and manufacturing
information.
The reference junction aids in the sensor's resistance to poisoning ions and helps
prolong sensor life. Rosemount 389/389VP sensors have a triple junction reference, which
protects the reference element from poisoning ions - such as ammonia, chlorine,
cyanides, and sulfides - in the process. Both models are made with anouter ceramic
junction constructed in an annualr design around the pH/ORP sensitive membrane.
The AccuGLASS
glass is a result of many years of glass research resulting in a formulation which has been
found to increase the life of the sensor. Unlike other pH glasses presently on the market,
this glass resists cracking, especially at higher temperatures, and reduces sodium ion
errors commonly found in high pH applications. Overall, the AccuGlass formulation
enhances the sensor performance to measure pH more accurately and have a longer
sensor life than ever before.
A choice of pH glass electrodes is available to best meet various application needs. Two
types are available: general purpose and high pH glass. The AccuGlass hemi bulb is the
standard glass offered on both types and can be used for most applications.
The Rosemount 389VP is configured with a Variopol (VP8) sensor-to-cable connector
which eliminates re-wiring and cable twisting when replacing sensors. The Variopol VP8
multiple pin connector option uses a mating VP cable. Once the cable is installed and
wired to the transmitter, sensors are easily replaced without replacing the cable and
without rewiring the transmitter. Also, the cable can be disconnected from the sensor
before removal from the process which eliminates cable twisting. VP8 cable assemblies
work with both VP8 and VP6 sensor connectors.
The Rosemount 389/389VP has a molded Tefzel body with Viton O-rings, making each
sensor very robust and chemically resistant. Complete encapsulation eliminates leakage or
high humidity problems traditionally found in other pH/ORP designs. The seimplified
construction, designed with user convenience in mind, does not require electrolyte (KCl)
replenishment or any high maintenance troubleshooting procedures.
Rosemount 389/389VP sensors are combintation sensors (pH, reference, and
temperature within sensor body) and measure pH or ORP (oxidation/reduction potential)
of aqueous solutions in pipelines, open tanks, or ponds. rosemount 389/389VP sensors are
suitable for virtually all applications and are compatible with Rosemount and other
manufacturers' instruments.
Reference Manual
™
pH glass formulations exceed industry standards. The AccuGlass pH
Description and Specifications
February 2019
5