Rosemount Model 3144 and 3244MV Smart Temperature Transmitters
3-20
If you are using two sensors with a Model 3244MV, repeat the
procedure for the second sensor. In Step 1, replace
1 Snsr 1 Config
with
2 Snsr 2 Config
.
If you are using a Rosemount dual element sensor with Callendar-Van
Dusen Constants, two tags are supplied. The two letters at the end of
the serial number on each tag (RW for Red/White and GB for
Green/Black), indicate the sensing element to which the constants on
that tag apply.
To disable the transmitter-sensor matching feature, refer to “Disable
Special Sensor” on page 3-6.
NOTE
Selecting
Not Used
at the “Enter Special Sensor” prompt will disable
transmitter-sensor matching. When you disable transmitter-sensor
matching, the transmitter reverts to either user or factory trim,
whichever was used previously.
Make certain the transmitter
engineering units default correctly before placing the transmitter into
service.
Output Trim
The
Digital-to-Analog Trim
command allows you to alter the
transmitter’s conversion of the input signal to a 4–20 mA output (see
Figure 3-2 on page 3-16). Adjust the analog output signal at regular
intervals to maintain measurement precision. To perform a
digital-to-analog trim, perform the following procedure:
1. From the Home screen, select
1 Device setup, 2 Diag/Service,
3 Calibration, 4 D/A trim
. Select
OK
after you set the control
loop to manual.
2. Connect an accurate reference meter to the transmitter at the
“Connect Reference Meter” prompt. To do so, connect the positive
lead to the positive terminal and the negative lead to the test
terminal in the transmitter terminal compartment. Refer to
Figure 2-3 on page 2-4, or shunt the transmitter power through
the reference meter at some point.
3. Select
OK
after connecting the reference meter.
4. Select
OK
at the “Setting fld dev output to 4 mA” prompt. The
transmitter outputs 4.00 mA.
System Accuracy Comparison at 150 °C Using a Pt 100 (a = 0.00385) RTD
with a Span of 0 to 200 °C
Standard Series 68 Sensor
Matched Series 68 Sensor
Model 3144
±0.10 °C
Model 3144
±0.10 °C
Standard 68 RTD
±1.05 °C
Matched 68 RTD
±0.18 °C
Total System
(1)
(1) Calculated using RSS statistical method:
±1.05 °C
Total System
±0.21 °C
Transmitter Accuracy
2
Sensor Accuracy
2
+
Total System Accuracy
=
HART Fast Keys
1,2,3,4
