PRESSURE AND LEVEL MEASUREMENT SYSTEMS
ABSTRACT
The sensor is a transducer that converts the measurand into signal carrying information.The present paper describes the construction of a fiber optic microbend sensor for the measurement of pressure and a water level sensor, which is a pulley and counterweight version of the float type level sensors. Optical fibers used for transmission of digital signals have a constant and lower attenuation. However, attenuation in optical fibers still occurs. Losses in fiber optic cables can be due to absorption, scattering or excessive bending. Bending losses due to external forces can be used to sense changes in the measurand for a fiber optic sensor. Micro bend sensors are intensity modulated type of fiber optic sensors. In these sensors, the light emitted from an optical source is carried along a fiber, its intensity is modified at the transducer and the light is returned to an optical detector.
Level measurement is an integral part of process control, and maybe used in a wide variety of industries. Float type sensors are liquid level sensors, which can operate well in a wide variety of liquids. The float and pulley gauge provides an ex¬cellent method of measuring large changes in level with accuracy. It has the advantage that the scale can be placed for convenient reading at any point within a reasonable distance of the tank or vessel. This paper suggests a float type of sensor that gives the level change as a function of the resistance change.
