47
48-635 E3 Modulevel
®
Displacer Level Transmitter
Intrinsic Safety
A design or installation approach that limits
the amount of energy that enters a hazardous area to elimi-
nate the potential of creating an ignition source.
Level
The present reading of the height of material in a vessel.
Linearity
The worst case error calculated as a deviation
from a perfect straight line drawn between two calibration
points.
Line Powered
See Four Wire.
Loop
The present reading of the 4–20 mA current output.
Loop Powered
See Two Wire.
Loop Resistance
The total value of the resistance in a two-
wire loop including equipment and wiring.
Low Voltage Directive
A European Community require-
ment for electrical safety and related issues of devices using
50–1000 VDC or 75–1500 VAC.
LVDT
Linear Variable Differential Transformer
This is the
mechanism by which the Electronic MODULEVEL measures
liquid level. This type of transformer compares the currents
induced in two secondary windings to determine the position
of the transformer core and, therefore, the liquid level.
Measured Value
The typical measurement values used to
track the level of a process: Level, % Output and Loop.
Media
The liquid material being measured by the level
transmitter.
Multidrop
The ability to install, wire, or communicate with
multiple devices over one cable. Each device is given a unique
address and ID.
Non-hazardous Area
An area where no volatile mixtures of
vapors/gas and oxygen will be found at any time.
Also called
General Purpose Area.
Non-incendive
A circuit in which any arc or thermal effect
produced, under intended operating conditions of the equip-
ment or due to opening, shorting, or grounding of field
wiring, is incapable, under specific test conditions, of igniting
the flammable gas, vapor, or dust-air mixture.
Password
A numerical value between 0 and 255 that pro-
tects stored configuration data from unauthorized manipula-
tion.
Percent (%) Output
The present reading as a fraction of
the 16mA scale (4–20mA).
Poll Address (HART ID)
A number between 1 and 15
which sets an address or location of a device in a multi-drop
loop. Poll address for single device configuration is 0.
Primary Winding
The inductor within a transformer to
which the voltage source is connected and which, as a result,
produces the magnetic field.
QuickStart
The essential information needed for the
E3 MODULEVEL to be installed, wired and calibrated.
Range
The maximum value to which the control may sense
level. In the case of the MODULEVEL, this value is limited
to the physical size of the displacer.
Repeatability
The maximum error between two or more
output readings of the same process condition.
RFI
Radio Frequency Interference
Electrical noise that can
have an adverse affect on electrical circuits, particularly low-
power devices.
Secondary Winding
The inductor within a transformer in
which current is induced by the magnetic field of the primary
winding.
Span
The whole or some portion of difference between the
upper and lower limits of the range, which is chosen by the
user.
Specific Gravity (SG)
The ratio of the density of a material
to the density of water at the same conditions.
Status
The current state of the transmitter’s diagnostics;
screen updates every 10 seconds.
Stilling Well
A device, usually a tube or pipe, which encloses
the sensing element of a level control in order to protect it
from and minimize the effects of turbulence in the vessel. To
ensure that the level in the well is identical to that outside the
well, it must have vent holes included near the top to allow
escape of vapor trapped above the liquid level.
Transformer
An electrical device which transfers electrical
energy from a primary winding to one or more secondary
windings by magnetic induction (no electrical contact)
Trim 4/Trim 20
Built-in system capability to fine tune the
4 mA and 20 mA points so the transmitter output
corresponds exactly to user’s meter, DCS input, etc.
Two Wire
An electrical instrument design that uses one set
of wires to provide both the supply power and process meas-
urement signal. The process measurement is achieved by vary-
ing the current of the loop. Also called
Loop Powered.
Units
The engineering units used to measure the level in
the system.
Warning (message)
The second level in the hierarchy of
Diagnostics annunciating conditions that are not fatal but
may affect measurement. A message will occur on the main
(rotating) screen when a Warning is detected but will not
affect output current. Further information can be obtained
by viewing the Status or Diagnostic screens.
