Novel Fiber-Optical Refractometric Sensor Employing Hemispherically-Shaped Detection Element
We present the theoretical and experimental data on the performance of the novel fiber-optic refractometric sensor that employs the hemispherical optical detection element. We exploit the sensitivity of internal reflection of light on the element’s spherical surface to the refractive index of the surrounding medium, several internal reflections in series, and the focussing properties of the concave spherical surface to achieve the enhanced sensitivity and reduce the intrinsic optical loss in the sensor. We show that the transmission function of the new sensor can easily be modified in the wide interval of the refractive index of the surrounding medium. This new sensor may find applications in different instruments. Key-Words:Optoelectronics, instrumentation, refractive index measurement, liquid level measurement.
A Prototype Fiber-Optic Discrete Level-Sensor for Liquid Propane-Butane
This paper describes a fiber-optic level sensor designed to measure the level of liquid propane-butane in a relatively short range (60 cm) in the top part of storage tanks at oil refineries with the purpose of monitoring the level of this product in the filled or slightly underfilled or overfilled tanks during various measuring operations. A discrete multi-element device employing novel refractometric transducers was selected because it yields both a large measurement range and high resolution. Several innovations offer a competitive advantage to industrial users: 1) Special micro-optical refractometric transducer; 2) Efficient and economical sensor multiplexing scheme; 3) Fast leveltracking operational algorithm. The vertical resolution of the sensor −1 cm, the maximum excess pressure in the tank −40 atm (4 MPa). The sensor has the spark-proof and explosion-proof design and optical fiber interface for the transmission of the output data. The sensor successfully measured liquid propane-butane level in storage tanks during numerous cycles of measuring operations. key words: liquid level measurement, ber-optic sensor, liquid
Long Ceramic Beam Tubes for Accelerator Magnets
The ceramic beam tubes for the fast and abort kickers and the bucker and pinger magnets used at Fermilab must meet a number of exacting requirements. The tubes must be long and sufficiently straight so as not to limit magnet design. They must have wall strength capable of withstanding the atmospheric and mechanical forces encountered during construction and operation. Vacuum tight ceramic to stainless steel transitions must be of reasonable cost; they must also withstand high temperature processing and remain vacuum tight to the 10/sup -9/ Torr range. To remove the possibility of static charge buildup each tube must have a surface coating of indium oxide applied to the inner wall. This thin coating is difficult to achieve and requires the most careful attention to detail. The methods used at Fermilab to achieve these goals are presented in this paper.