Rosemount 3244MV, Справочное руководство

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Reference Manual
00809-0100-4799, Rev BA
September 2002
Model 3244MV
2-3
When commissioning more than one device on a profibus segment, it can
be difficult to identify which device is at a particular location. The
removable tag provided with the transmitter can aid in this process by
linking the Device ID and a physical location. The installer should note the
physical location in both places on the removable commissioning tag and
tear off the bottom portion. This should be done for each device on the
segment. The bottom portion of the tags can be used for commissioning
the segment in the control system.
Environmental
Temperature Environments
The transmitter will operate within specifications for ambient temperatures
between –40 and 185 °F (–40 and 85 °C).In a direct mounting configuration,
heat from the process is transferred from the thermowell to the transmitter
housing. If the expected process temperature is near or beyond the
specification limits, consider the use of additional thermowell lagging, an
extension nipple, or a remote mounting configuration to isolate the transmitter
from these excessive temperatures. Figure 2-1 provides an example of the
relationship between transmitter housing temperature rise and extension
length. Use Figure 2-1 and the accompanying example to determine
adequate thermowell extension length.
Figure 2-1. Transmitter Housing
Temperature Rise
EXAMPLE:
The rated temperature specification is 85 °C. If the maximum ambient
temperature is 40 °C and the temperature to be measured is 540 °C, the
maximum allowable housing temperature rise is the rated temperature
specification limit minus the existing ambient temperature (85 – 40), or
45 °C.
As shown in Figure 2-1, an extension (E) dimension of 3.6 inches will result
in a housing temperature rise of 22 °C. An “E” dimension of 4 inches would
therefore be the minimum recommended length and would provide a
safety factor of about 25 °C. A longer “E” dimension, such as 6 inches,
would be desirable in order to reduce errors caused by transmitter
temperature effect, although in that case the transmitter would probably
require extra support. If a thermowell with lagging is used, the “E”
dimension may be reduced by the length of the lagging.
HOUSING TEMPERA
T
UR
E R
ISE
ABO
VE AMBIENT °C (°F)
3 4 5 6 7 8 9
0
60 (108)
50 (90)
40 (72)
30 (54)
20 (36)
10 (18)
3044-0123A
3.6
22
Transmitter Housing
Temperature Rise vs.
Extension Length for
a Test Installation
EXTENSION LENGTH, INCHES (E)
815 °C (1,500 °F)
Oven Temperature
540 °C (1,000 °F)
Oven Temperature
250 °C (482°F)
Oven Temperature