Instruction manual

RFT9739 Field-Mount Transmitter Instruction Manual

RFT9739 Specifications

continued

Communication

Switch allows selection of preset or user-defined settings.

• Default preset-settings: HART protocol over Bell 202, on the primary

mA output, 1200 baud; Modbus protocol in RTU mode, on the RS-485

output, 9600 baud; 1 stop bit, odd parity.

• Default user-defined settings: HART protocol, on the RS-485 output,

1200 baud, 1 stop bit, odd parity.

Bell 202 signal is superimposed on primary variable mA output, and is

available for host system interface. Frequency 1.2 and 2.2 kHz,

amplitude 0.8 V peak-to-peak, 1200 baud. Requires 250 to 1000 ohms

load resistance.

RS-485 signal is a ±5 V square wave referenced to transmitter ground.

Baud rates between 1200 baud and 38.4 kilobaud can be selected.

Additional outputs Sensor frequency

For use with Micro Motion peripheral devices, 8 V peak-to-peak at

sensor natural frequency, referenced to sensor ground, 10 kohm output

impedance.

Sensor temperature

For use with Micro Motion peripheral devices, 5 mV/°C, referenced to

signal ground, 10 kohm output impedance.

API gravity

API gravity references to 60°F (15°C). Uses correlation based on API

equation 2540 for Generalized Petroleum Products.

Accuracy of corrected density calculation relative to API-2540 from 0 to

300°F:

Process fluid g/cc kg/m

°API

Diesel, heater, and fuel oils ±0.0005 ±0.5 ±0.2

Jet fuels, kerosenes, and solvents ±0.002 ±2.0 ±0.5

Crude oils and JP4 ±0.004 ±4.0 ±1.0

Lube oils ±0.01 ±10 ±2.0

Gasoline and naphthenes ±0.02 ±20 ±5.0

Minimum 4-20 mA span: 10°API

Standard volume

Outputs standard volume at 60°F or 15°C for Generalized Petroleum

Products when °API is selected as density unit of measure. Accuracy of

standard volume measurements depends on accuracies of mass flow

rate, density, temperature and temperature-corrected °API calculation,

and can be estimated using the root mean square method. Standard

volume accuracy of ±0.5% of rate is typically attainable for Generalized

Petroleum Products such as fuel oils, jet fuels, and kerosenes.