Submersion Mounting - Emerson Rosemount 389 Instruction Manual

WARNING!
IRRITANT
Internal electrolyte fill may cause skin or eye irritation.
Mounting guidelines
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In most cases, the sensor can simply be installed as shipped, and you can obtain readings
with an accuracy of ±0.2 pH. To obtain greater accuracy or to verify proper operation, the
sensor must be calibrated as a loop with its compatible analyzer or transmitter.
2.2.1

Submersion mounting

Rosemount 389 and 389VP sensors have a 1 in. MNPT process connection at the back of
the sensor.
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Instruction Manual
Shake down the sensor to remove any air bubbles that may be present inside the tip
of the pH glass.
Do not install the sensor horizontally. The sensor must be 10 º off the horizontal to
ensure accuracy.
Do not install the sensor upside down.
With the standard recessed electrode, air bubbles may become trapped in the
sensor end. This problem is most commonly encountered in areas of low flow or
during calibration. Shake the probe while it is immersed in solution to remove
bubbles.
Using a standard 1 in. union, mount the sensor to a 1 in. SCH 80 CPVC or PVDF
standpipe.
Tapered pipe threads in plastic tend to loosen after installation. We therefore
recommend that you use Teflon tape on the threads and check the tightness of the
connection frequently to ensure that no loosening has occurred.
To prevent rain water or condensation from running into the sensor, use a
weatherproof junction box (see Figure 2-3).
Installation
9