Apparatus and method for monitoring the presence of a conductive media

Patent · Mon Jan 01 00:00:00 EST 1979

OSTI ID:863408

DuVall, Bruce W ^[1]; Valentine, James W ^[1]; Morey, Kenneth O ^[1]

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1. Colorado Springs, CO

An inductive level sensor has inductively coupled primary and secondary windings. Circuitry drives the primary with an AC signal of constant current magnitude and selected frequency f to induce in the secondary, a voltage signal V of magnitude .vertline.V.vertline., frequency f and phase difference .phi. from the driving signal. Circuitry operates to generate a voltage output signal proportional to .vertline.V.vertline. cos (.phi.-.theta.), where .theta. is a selectively set phase shift factor. By properly and selectively adjusting the frequency f and phase shift factor .theta., an output signal .vertline.V.vertline. cos (.phi.-.theta.) can be provided which self-compensates for changes in mutual inductance caused by operating temperature variations so that an output signal is produced which is substantially linearly proportional to changes in the level of a pool of liquid metal being monitored. Disclosed also is calibration circuitry and circuitry for converting the voltage signal .vertline.V.vertline. cos (.phi.-.theta.) into a current signal.

• DOE Contract Number: N4889004P
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4164146
• OSTI ID: 863408
• Country of Publication: United States
• Language: English

Related Subjects

apparatus
method
monitoring
presence
conductive
media
inductive
level
sensor
inductively
coupled
primary
secondary
windings
circuitry
drives
signal
constant
current
magnitude
selected
frequency
induce
voltage
vertline
phase
difference
phi
driving
operates
generate
output
proportional
cos
theta
selectively
set
shift
factor
properly
adjusting
provided
self-compensates
changes
mutual
inductance
caused
operating
temperature
variations
produced
substantially
linearly
pool
liquid
metal
monitored
disclosed
calibration
converting
selected frequency
secondary windings
secondary winding
substantially linear
temperature variations
constant current
level sensor
phase difference
signal proportional
voltage signal
voltage output
inductively coupled
phase shift
liquid metal
output signal
operating temperature
current signal
temperature variation
mutual inductance
current magnitude
/73/