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5081 Transmitter - Rosemount

5081 Rosemount Two-Wire Transmitters
The Model 5081 family of transmitters can be used to measure pH, ORP, conductivity (using either contacting or toroidal sensors), resistivity, oxygen (ppm and ppb level), free chlorine, total chlorine, and ozone in a variety of process liquids.

The transmitter has a rugged, weatherproof, corrosion-resistant enclosure (NEMA 4X and IP65) of epoxy-painted aluminum. The enclosure also meets NEMA 7B explosion-proof standards.

The transmitter has a two-line seven-segment display. The main measurement appears in 0.8-inch (20 mm) high numerals. The secondary measurement, temperature (and pH if free chlorine is being measured), appears in 0.3-inch (7 mm) high digits.

Two digital communication protocols are available: HART (model option -HT) and Foundation Fieldbus (model options -FF or -FI). Digital communications allows access to AMS (Asset Management Solutions). Use AMS to set up and configure the transmitter, read process variables, and troubleshoot problems from a personal computer or host anywhere in the plant.

A handheld infrared remote controller or the HART and Foundation Fieldbus Model 375 communicator can also be used for programming and calibrating the transmitter. The remote controller works from as far away as six feet.




Cast aluminum containing less than 6% magnesium, with epoxy polyester coating. NEMA 4X (IP65) and NEMA 7B. Neoprene O-ring cover seals.


See Drawing 

Conduit Openings:

3/4-in NPT

Ambient Temperature:

-4 to 149°F (-20 to 65°C)

Storage Temperature:

-22 to 176°F (-30 to 80°C)

Relative Humidity:

0 to 95% (non-condensing

Weight/Shipping Weight:

10 lb/11 lb (4.5/5.0 kg)


Two-line LCD; first line shows process variable (pH, ORP, conductivity, % concentration, oxygen, ozone, or chlorine), second line shows process temperature and output current. For pH/chlorine combination, the second line can be toggled to show pH. Fault and warning messages, when triggered, alternate with temperature and output readings.
First line: 7 segment LCD, 0.8 in. (20 mm) high.
Second line: 7 segment LCD, 0.3 in. (7mm) high.
Display board can be rotated 90 degrees clockwise or counterclockwise.
During calibration and programming, messages and prompts appear in the second line.

Temperature resolution:


Hazardous Location Approval:

For details, see specifications for the measurement of interest.



Digital Communications:

For details, see specifications for the measurement of interest.