Fiber optical liquid level sensor under cryogenic environment

This paper reports a preliminary experimental investigation and characteriz ation of an optical fiber-based liquid level detection system for applicati ons in cryogenic environment. The sensor system comprises a multiplexed arr ay of point liquid probes. Two different designs of the probe were fabricat ed 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 a ddition, response time of the liquid probe was measured and compared experi mentally. (C) 2001 Elsevier Science B.V. All rights reserved.