3
48-651 SIL Certified Safety Manual for E3 Modulevel
®
1.0 Introduction
1.1 Product Description
The E3 MODULEVEL is a loop-powered, two-wire,
24 VDC level transmitter that uses simple buoyancy princi-
ples in combination with a precision range spring and a
highly accurate LVDT (linear variable differential trans-
former) to detect and convert liquid level changes into a
stable 4–20 mA output signal.
NOTE: For Safety Instrumented Systems usage, it is assumed that the
4–20 mA output is used as the safety variable.
The analog output from the E3 MODULEVEL meets the
NAMUR NE 43 standard (3.8 mA to 20.5 mA usable). The
transmitter contains self-diagnostics and is programmed to
drive the output to a user-selected failure state, either low or
high, upon internal detection of a diagnostic indicator. The
device can be equipped with or without an optional non-
interfering graphic liquid crystal display (LCD).
Table 1 indicates the version of the E3 MODULEVEL
transmitter that has been certified for SIL 2/3 applications.
1.2 Theory of Operation
The E3 MODULEVEL Displacer Level Transmitter relies
on the principles of buoyancy to convert mechanical move-
ment to an electronic output.
The movement of the range spring, as it compresses or elon-
gates based on the volume of displacer submerged in the
liquid, causes movement of a special LVDT core attached to
the spring. The LVDT technology converts the movement
of the LVDT core within the LVDT to a stable 4–20 mA
output signal. The position of the core, with respect to a
primary and two secondary windings, induces voltage in
each winding. The comparison of the induced voltages
within the microprocessor of the E3 MODULEVEL results
in very accurate level or interface level output.
The E3 MODULEVEL can, alternatively, be set up to track
the changing density of a liquid over a known density range
and convert that into a stable 4–20 mA output signal. As the
density of the liquid changes, so does the mass of the liquid
displaced by the displacer. This resulting change in buoyancy
force on the displacer causes movement of the LVDT core
needed to convert the density change to the 4–20 mA signal.
1 Transmitters:
Model E3 MODULEVEL,
E3X-XXXX-SXX (HART)
Hardware Version (or later)
Analog Board 030-2475-001 + -003 Rev E
Digital Board 030-9145-001 Rev AG
Wiring Board 030-9151-001 Rev Q
Software Version (or later)
Model E3 HT 1.1cA.mot
Table 1
Enhanced E3 MODULEVEL
Model Numbers
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