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
Political Developments: Some Conclusions and an Interpretation
When the political decisions and achievements of the post-Khrushchev Soviet leadership are considered as a whole, it is not immediately obvious that there is any pattern to them. It may, nevertheless, be useful to begin by devoting attention to some of the major policy tendencies and outcomes of the past decade, most of which have already been considered in greater detail by other contributors, before going on to enquire if any broad strategy underlying them may be discerned and to attempt to place the various changes in a broader political context.