7ML19985GE04
SITRANS LC500 – OPERATING INSTRUCTIONS
Page 105
Appendix F
Appendix F: Approvals
The operation of the SITRANS LC500 conforms to the following:
NAMUR recommendation NE 43
This recommendation describes rules by which analog transmitters transfer their
information to DCS equipment. This information can be divided into two types:
•
measurement information
For measurement information the current signal should be within the range of
3.8 to 20.5 mA.
•
failure signalling
For failure information which indicates a failure in the measuring system
1
the
current signal should be in the range of either 0 to 3.6 mA, or 21 mA or greater.
The application will determine which of these two ranges is more desirable. The
SITRANS LC500 can be set for 3.6 mA, or 22 mA, as required
2
.
1.
It may also signal a process level outside the Upper and Lower Sensor Limits, if
the unit has been programmed for this. For more information, see
Fault
Signalling
on page 16.
2.
See
Analog Fault Signalling (2-state)
on page 67 for details.