5081–A Amperometric Transmitter
•  MEASURES dissolved oxygen (ppm and ppb level), free chlorine, total chlorine, and ozone
•  SECOND INPUT FOR A pH SENSOR ALLOWS AUTOMATIC pH CORRECTION for free chlorine measurement. No expensive, messy reagents needed
•  AUTOMATIC BUFFER RECOGNITON FOR pH CALIBRATION

5081–P pH/ORP Transmitter
•  CHANGING FROM pH to ORP operation takes only seconds
•  AUTOMATIC TWO-POINT BUFFER CALIBRATION reduces errors
•  SOLUTION TEMPERATURE COMPENSATION converts measured pH to the pH at 25°C
•  CONTINUOUS DIAGNOSTICS monitor sensor performance and warn the user of failure (FAULT) or approaching failure (WARNING)

5081–C Contacting Conductivity Transmitter
•  MEASURES CONDUCTIVITY, RESISTIVITY, OR CUSTOM CURVE VARIABLE
•  AUTOMATIC TC RECOGNITION simplifies start up
•  AUTOMATIC/MANUAL TEMPERATURE COMPENSATION ensures accurate monitoring and control
•  AUTOMATIC COMPENSATION FOR SENSOR CABLE RESISTANCE improves accuracy of high conductivity/ low resistivty measurements *
•  BUILT-IN TEMPERATURE COMPENSATION ALGORITHMS include straight slope, ultrapure water, cation conductivity, and no compensation

5081–T Toroidal Conductivity Transmitter
•  MEASURES CONDUCTIVITY, PERCENT CONCENTRATION, OR CUSTOM CURVE VARIABLE
•  AUTOMATIC TC RECOGNITION simplifies start up
•  AUTOMATIC/MANUAL TEMPERATURE COMPENSATION ensures accurate monitoring and control
•  BUILT-IN CONCENTRATION CURVES for 0-12% NaOH, 0-15% HCl, 0-25% and 95-99.7% H2SO4
•  PROGRAMMABLE REFERENCE TEMPERATURE enables temperature compensation to temperatures other than 25 degrees Celsius
•  AUTOMATIC COMPENSATION FOR SENSOR CABLE RESISTANCE improves accuracy of high conductivity measurements

FEATURES AND APPLICATIONS
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 5081 is compatible with most Rosemount Analytical sensors. See the Specification sections for details.

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" (20 mm) high numerals. The secondary measurement, temperature (and pH if free chlorine is being measured), appears in 0.3" (7 mm) high digits.

Two digital communication protocols are available: HART (model option -HT) and FOUNDATION fieldbus (model option -FF). 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 Model 275 communicator can also be used for programming and calibrating the transmitter. The remote controller works from as far away as six feet.

® FOUNDATION is a registered trademark of fieldbus Foundation.
*Patent pending

Enclosure: Cast aluminum containing less than 6% magnesium, with epoxy polyester coating. NEMA 4X (IP65) and NEMA 7B. Neoprene O-ring cover seals.
Conduit Openings: ¾" 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)
Display: 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: 0.1°C
Hazardous Location Approval: For details, see specifications for the measurement of interest.
RFI/EMI: EN-61326
Digital Communications: For details, see specifications for the measurement of interest.
HART —
Power & Load Requirements:
Supply voltage at the transmitter terminals should be at least 12 Vdc. Power supply voltage should cover the voltage drop on the cable plus the external load resistor required for HART communications (250 Ω minimum). Minimum power supply voltage is 12 Vdc. Maximum power supply voltage is 42.4 Vdc (30 Vdc for intrinsically safe operation). The graph shows the supply voltage required to maintain 12 Vdc (upper line) and 30 Vdc (lower line) at the transmitter terminals when the current is 22 mA.
Analog Output: Two-wire, 4-20 mA output with superimposed HART digital signal. Fully scalable over the operating range of the sensor.
Output accuracy: ±0.05 mA
FOUNDATION FIELDBUS—
Power & Load Requirements: A power supply voltage of 9-32 Vdc at 22 mA is required.
Fieldbus Intrinsically Safe COncept/FISCO-compliant versions of Model 5081 Foundation Fieldbus transmitter are available.