Moist Or Corrosive Environments; Location And Position - Emerson Rosemount 3144P Reference Manual

Reference Manual
00809-0100-4021, Rev JA
Example
The maximum permissible housing temperature rise (T) can be calculated by subtracting the maximum
ambient temperature (A) from the transmitter's ambient temperature specification limit (S). For
instance, if A = 40 °C.
For a process temperature of 540 °C (1004 °F), an extension length of 3.6-in (91.4 mm) yields a housing
temperature rise (R) of 22 °C (72 °F), providing a safety margin of 23 °C (73 °F). A 6.0-in.(152.4 mm)
extension length (R = 10 °C [50 °F]) offers a higher safety margin (35 °C [95 °F]) and reduces
temperature-effect errors but would probably require extra transmitter support. Gauge the
requirements for individual applications along this scale. If a thermowell with lagging is used, the
extension length may be reduced by the length of the lagging.
2.2.4

Moist or corrosive environments

The Rosemount 3144P Transmitter has a highly reliable dual compartment housing designed to resist
moisture and corrosion. The sealed electronics module is mounted in a compartment that is isolated
from the terminal side with conduit entries. O-ring seals protect the interior when the covers are
properly installed. In humid environments, however, it is possible for moisture to accumulate in conduit
lines and drain into the housing.
Note
Each transmitter is marked with a tag indicating the approvals. Install the transmitter according to all
applicable installation codes, and approval and installation drawings (see
Certifications). Verify that the operating atmosphere of the transmitter is consistent with the hazardous
locations certifications. Once a device labeled with multiple approval types is installed, it should not be
reinstalled using any of the other labeled approval types. To ensure this, the approval label should be
permanently marked to distinguish the approval type(s) used.
2.2.5

Location and position

When choosing an installation location and position, take access to the transmitter into account.
Terminal side of electronics housing
Mount the transmitter so the terminal side is accessible, allowing adequate clearance for cover removal.
Best practice is to mount the transmitter with the conduit entries in a vertical position to allow for
moisture drainage.
Circuit side of electronics housing
Mount the transmitter so the circuit side is accessible, providing adequate clearance for cover removal.
Additional room is required for LCD display installation. The transmitter may be mounted directly to or
remotely from the sensor. Using optional mounting brackets, the transmitter may be mounted to a flat
surface or a 2.0-in. (50.8 mm) diameter pipe (see
Installation
T = S – A
T = 85 °C – 40 °C
T = 45 °C
"Mounting" on page
Installation
April 2017
Appendix B: Product
13).
9