<title>A digital liquid level sensor system based on parallel fiber sensor heads</title>

One of the difficult duties in chemical industrial units is the determination of the level of liquid for real – time monitoring. Determination of this parameter is useful in process control loop. Hence present study is devoted for this purpose by employing microbend based optical fiber sensor. In this work, in order to continuously monitor liquid level in petroleum and chemical industries, an optical fiber sensor based on microbend effect was designed and implemented. The system is consist of a sensor that is composed of a microbend modulator, sensing fiber, emitting / detecting devices, in addition to liquid container unit, and an electronic circuit that was used to control the liquid level. The results showed that the laser technique is both accurate and immediate.

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Power-Type Liquid-Level Sensor for High Refractive Index Liquid Based on Long-Period Fiber Grating

Sensors and Actuators A Physical ◽

10.1016/j.sna.2021.112652 ◽

2021 ◽

pp. 112652

Author(s):

Ming Zhang ◽

Zhangjun Hu ◽

Xiao Wang ◽

Linlin Xue ◽

Jun Zou ◽

...

Keyword(s):

Refractive Index ◽

High Refractive Index ◽

Liquid Level ◽

Fiber Grating ◽

Power Type ◽

Long Period Fiber Grating ◽

Long Period ◽

Level Sensor ◽

Period Fiber Grating ◽

Liquid Level Sensor

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Liquid level sensor based on dynamic Fabry–Perot interferometers in processed capillary fiber

Scientific Reports ◽

10.1038/s41598-021-82193-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Pablo Roldán-Varona ◽

Rosa Ana Pérez-Herrera ◽

Luis Rodríguez-Cobo ◽

Luis Reyes-González ◽

Manuel López-Amo ◽

...

Keyword(s):

Optical Fiber Sensor ◽

Liquid Level ◽

Hollow Core ◽

Immiscible Liquids ◽

Fabry Perot ◽

Detection Mode ◽

Level Sensor ◽

Core Fiber ◽

Liquid Level Sensor ◽

Silica Capillary

AbstractIn this work, a novel optical fiber sensor capable of measuring both the liquid level and its refractive index is designed, manufactured and demonstrated through simulations and experimentally. For this, a silica capillary hollow-core fiber is used. The fiber, with a sensing length of 1.55 mm, has been processed with a femtosecond laser, so that it incorporates four holes in its structure. In this way, the liquid enters the air core, and it is possible to perform the sensing through the Fabry–Perot cavities that the liquid generates. The detection mode is in reflection. With a resolution of 4 μm (liquid level), it is in the state of the art of this type of sensor. The system is designed so that in the future it will be capable of measuring the level of immiscible liquids, that is, liquids that form stratified layers. It can be useful to determine the presence of impurities in tanks.

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Light Path Model of Fiber Optic Liquid Level Sensor Considering Residual Liquid Film on the Wall

Journal of Sensors ◽

10.1155/2015/729507 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8

Author(s):

Zhijun Zhang ◽

Shiwei Zhang

Keyword(s):

Liquid Film ◽

Fiber Optic ◽

Glass Tube ◽

Path Model ◽

Liquid Level ◽

Residual Liquid ◽

Light Refraction ◽

Special Cases ◽

Level Sensor ◽

Liquid Level Sensor

The working principle of the refractive-type fiber optic liquid level sensor is analyzed in detail based on the light refraction principle. The optic path models are developed in consideration of common simplification and the residual liquid film on the glass tube wall. The calculating formulae for the model are derived, constraint conditions are obtained, influencing factors are discussed, and the scopes and skills of application are analyzed through instance simulations. The research results are useful in directing the correct usage of the fiber optic liquid level sensor, especially in special cases, such as those involving viscous liquid in the glass tube monitoring.

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