High accuracy electronic material level sensor
Abstract
The High Accuracy Electronic Material Level Sensor (electronic dipstick) is a sensor based on time domain reflectometry (TDR) of very short electrical pulses. Pulses are propagated along a transmission line or guide wire that is partially immersed in the material being measured; a launcher plate is positioned at the beginning of the guide wire. Reflected pulses are produced at the material interface due to the change in dielectric constant. The time difference of the reflections at the launcher plate and at the material interface are used to determine the material level. Improved performance is obtained by the incorporation of: (1) a high accuracy time base that is referenced to a quartz crystal, (2) an ultrawideband directional sampler to allow operation without an interconnect cable between the electronics module and the guide wire, (3) constant fraction discriminators (CFDs) that allow accurate measurements regardless of material dielectric constants, and reduce or eliminate errors induced by triple-transit or ``ghost`` reflections on the interconnect cable. These improvements make the dipstick accurate to better than 0.1%. 4 figs.
- Inventors:
- Issue Date:
- Research Org.:
- Univ. of California (United States)
- OSTI Identifier:
- 445711
- Patent Number(s):
- 5610611
- Application Number:
- PAN: 8-510,980
- Assignee:
- Univ. of California, Oakland, CA (United States)
- DOE Contract Number:
- W-7405-ENG-48
- Resource Type:
- Patent
- Resource Relation:
- Other Information: PBD: 11 Mar 1997
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 44 INSTRUMENTATION, INCLUDING NUCLEAR AND PARTICLE DETECTORS; LEVEL INDICATORS; MEASURING METHODS; PERFORMANCE; DESIGN; PULSE DISCRIMINATORS; PULSES; REFLECTION
Citation Formats
McEwan, T E. High accuracy electronic material level sensor. United States: N. p., 1997.
Web.
McEwan, T E. High accuracy electronic material level sensor. United States.
McEwan, T E. Tue .
"High accuracy electronic material level sensor". United States.
@article{osti_445711,
title = {High accuracy electronic material level sensor},
author = {McEwan, T E},
abstractNote = {The High Accuracy Electronic Material Level Sensor (electronic dipstick) is a sensor based on time domain reflectometry (TDR) of very short electrical pulses. Pulses are propagated along a transmission line or guide wire that is partially immersed in the material being measured; a launcher plate is positioned at the beginning of the guide wire. Reflected pulses are produced at the material interface due to the change in dielectric constant. The time difference of the reflections at the launcher plate and at the material interface are used to determine the material level. Improved performance is obtained by the incorporation of: (1) a high accuracy time base that is referenced to a quartz crystal, (2) an ultrawideband directional sampler to allow operation without an interconnect cable between the electronics module and the guide wire, (3) constant fraction discriminators (CFDs) that allow accurate measurements regardless of material dielectric constants, and reduce or eliminate errors induced by triple-transit or ``ghost`` reflections on the interconnect cable. These improvements make the dipstick accurate to better than 0.1%. 4 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Mar 11 00:00:00 EST 1997},
month = {Tue Mar 11 00:00:00 EST 1997}
}