Honeywell STT25D, Operator'S Manual

Page: 21 / 40

18 Smart Temperature Transmitter STT250 – Operator Manual
B-B section
(80 )
(40 )
2 x M4
A-A section
(100 )
1/2"
NPT or
M20
1/2" NPT
(33)
46188454-0XX
Figure 13: Stainless Steel Direct Head Mount Housing Dimensions
For more detailed installation drawings, refer to the list in section 5.4.
4.7 Commissioning
Commissioning is carried out after installation and wiring have been completed. Power
up the STT250 transmitter and verify via the SFC or HART Communicator that it is
configured as required. If a bench check and configuration were completed, the
procedure will be clear. If no bench check and configuration was done, refer to
Section 4.4 and carry it out now. Verify also that the receiving device is actually
receiving the output signal and use the SFC or HART Communicator in output mode
to vary the output signal and verify loop calibration. If small errors exist in the loop
then they should be identified and the out of specification device calibrated. However,
if no adjustment is possible (e.g. with voltage developing resistors or active barriers)
then the STT250 output can be recalibrated to compensate for loop zero and span
errors. For calibration of the STT250, refer to the SFC Operating Guide 34-ST-11-16.
4.8 Start Up
Start up the process, check that the STT250 environment is still as expected (i.e. local
temperature and vibration are not excessive), housing cover is tightly sealed and
mountings are secure.
If the process operates at a slightly different condition from expected then the range of
the STT250 can be easily changed by keying in a new URV/LRV setting via the
SFC(DE) or the HART Communicator and rescaling the receiving device.