Sensor 2 Serial Number; 2-Wire Rtd Offset; Terminal Temperature; Dual-Sensor Configuration - Emerson Rosemount 3144P Reference Manual

Reference Manual
00809-0100-4021, Rev AA
March 2002
Dual-Sensor
Configuration
HART Fast Keys 1, 3, 3

Sensor 2 Serial Number

HART Fast Keys 1, 3, 2, 4, 3
The Sensor 2 S/N variable provides a location to list the serial number of a
second sensor.

2-Wire RTD Offset

HART Fast Keys 1, 3, 2, 3, 6
The 2-wire Offset command allows the user to input the measured lead wire
resistance, which will result in the transmitter adjusting its temperature
measurement to correct the error caused by this resistance. Due to a lack of
lead wire compensation within the RTD, temperature measurements made
with a 2-wire RTD are often inaccurate.
To utilize this feature perform the following steps:
1. Measure the lead wire resistance of both RTD leads after installing the
2-wire RTD and the Model 3144P.
2. From the HOME screen, select 1 Device Setup, 3 Configuration,
2 Sensor Configuration, 3 Sensor 1 Setup, 6 2-Wire Offset.
3. Enter the total measured resistance of the two RTD leads at the 2-Wire
Offset prompt. Enter this resistance as a negative (–) value to ensure
proper adjustment.The transmitter then adjusts its temperature
measurement to correct the error caused by lead wire resistance.
4. Repeat Steps 1 through 3 for sensor 2, selecting 1 Device Setup, 3
Configuration, 2 Sensor Configuration, 4 Sensor 2 Setup, 6 2-Wire
Offset.

Terminal Temperature

HART Fast Keys 1, 3, 2, 5
The Terminal Temp command sets the terminal temperature units to indicate
the temperature at the transmitter terminals.
Dual-sensor configuration allows configuration of the functions that can be
used with a dual-sensor configured transmitter. This includes Differential
Temperature, Average Temperature, First Good Temperature, Hot Backup,
and Sensor Drift Alert.

Differential Temperature

HART Fast Keys 1, 3, 1, 5, 3
The Model 3144P configured for a dual-sensor can accept any two inputs and
display the differential temperature between them. Use the following
procedure to configure the transmitter to measure differential temperature.
First, configure Sensor 1 and Sensor 2 appropriately. Select 1 Device Setup,
3 Configuration, 2 Sensor Configuration, 1 Change type/conn to set the
sensor type and number of wires for Sensor 1. Repeat for Sensor 2.
NOTE
This procedure reports the differential temperature as the primary variable
analog signal. If this is not necessary, assign differential temperature to the
secondary, tertiary, or quaternary variable.
Model 3144P
3-12