Optical Liquid Level Sensor Research Articles

A smart optical liquid level sensor based on Hg cladding optical waveguide

A smart optical liquid level sensor based on the theory of connected vessels is introduced. The Hg cladding optical waveguide (HCOW) is taken as its probe, and the change of liquid level is presented by the change of the HCOW length. Both the theoretical analysis and experiments show that when the waveguide diameter and the light wavelength are certain, the optical power loss decreased linearly with the increase of the HCOW length. By detecting the power loss of HCOW, optimizing the structure of probe and selecting the appropriate apparatus for detection, the real time detection of liquid level with high precision can be got. The experimental results show that the measurement accuracy is 5.2 mm within 10 m liquid level, and its theoretical precision can be up to 0.02%.

All in one optical liquid level sensor from Gentech

All in one optical liquid level sensor from Gentech

Fiber optical liquid level sensor under cryogenic environment

Abstract This paper reports a preliminary experimental investigation and characterization of an optical fiber-based liquid level detection system for applications in cryogenic environment. The sensor system comprises a multiplexed array of point liquid probes. Two different designs of the probe were fabricated and tested. Probe tests were conducted in water–air, liquid–gas nitrogen environments. The multiplexing of multiple liquid probes using an optical time domain reflectometer (OTDR) device was successfully demonstrated. In addition, response time of the liquid probe was measured and compared experimentally.

Split analog-to-digital converter for intensity-modulated optical fiber sensors

A technique is described which provides a linear pulse-position modulated signal from an intrinsically analog remote optical sensor having a nonlinear response to the sensed parameter. The technique is applied to a differential absorption optical liquid level sensor. Sensor and system performance are presented.