Abstract: The invention relates to optical devices for sensing and measuring various physical parameters. More particularly, this invention relates to an optical device having a spectral modulation sensor in which the physical parameter being measured causes spectral changes in the reflectivity and/or transmission of the sensor's optically resonant structure, thereby spectrally modulating the output light from the sensor as a function of the physical parameter being measured.

Abstract: An arrangement for sensing temperature changes at an object, specifically within a transformer or the like, is disclosed herein. In one embodiment, this arrangement utilizes as one of its main components a sensor including a solid glass medium which changes in optical density with changes in temperature, a single optical fiber for directing a beam of light into the glass media, a single optical fiber for collecting the light transmitted through the medium, and an optical means for imaging the transmitted light to the collecting fiber. In addition, in this embodiment, the light is caused to pass through the glass medium such that the amount of light reaching the collecting fiber is linearly dependent upon the temperature at the medium with respect to temperatures within a wide range.

Abstract: A device for sensing temperature changes at an object, specifically within a transformer or the like, is disclosed herein. This device utilizes an electrically non-conductive sensor including a temperature responsive substance having the characteristic of changing in optical density with changes in temperature. In order to detect changes and/or to actually monitor the temperature the device provides means for detecting and/or monitoring the optical density of the temperature responsive means, thereby indicating the temperature at the object.

Abstract: Nonthermal and uncomplicated means and method of degassing a liquid are disclosed. The liquid degassing means includes a normally lower liquid vessel, a normally upper vapor vessel, evacuation means, and valved conduit means interconnecting with the liquid and vapor vessels and evacuation means. A trace gas manometer connecting with the liquid vessel is preferably included to measure the residual gas content at any time. The liquid degassing means is agitated to obtain good mixing of the liquid and vapor so that gas in the vapor is in equilibrium with gas dissolved in the liquid. The fluid is then transferred to the lower liquid and manometer vessels, and gas-laden vapor is isolated from the liquid and evacuated from the vapor vessel to remove a large amount of gas along with a relatively small amount of liquid in vapor form. The cycle is repeated until the necessary fluid purity is attained.