An optical sensor is described for distinguishing between liquids of different refractive index, through strength of interference caused by an optical cavity having an exposed optical boundary in contact with such liquids. The sensor may be used, for example, to distinguish between water and aviation fuel in an aircraft fuel tank.

An optical sensor is described for distinguishing between liquids of different refractive index, through strength of interference caused by an optical cavity having an exposed optical boundary in contact with such liquids. The sensor may be used, for example, to distinguish between water and aviation fuel in an aircraft fuel tank.

A multiple sensor fiber optic sensing system includes an optical fiber having at least first fiber optic sensors and second fiber optic sensors deployed along its length. In response to an interrogating pulse, the first fiber optic sensors generate responses in a first optical spectrum window, and the second fiber optic sensors generate responses in a second, different optical spectrum window. The responses in the first optical spectrum window are measured in a first optical spectrum channel, and the responses in the second optical spectrum window are measure in a second, different optical spectrum channel and provide simultaneous indications of one or more parameters, such as temperature and pressure, in the environment in which the sensors are deployed.

The present disclosure relates to the display technical field, more particularly, to a pressure sensitive film and a manufacturing method thereof. The pressure sensitive film comprises a substrate, a color displaying layer and a color forming layer laminated sequentially; the other surface of the substrate opposite to the surface adjoining the color displaying layer is for bearing pressure; the color forming layer comprises at least one color forming unit, each of which comprises at least two color sacs, and the at least two color sacs have pressure-bearing thresholds different from each other, and operate when the pressure borne reaches their pressure-bearing thresholds; the color displaying layer displays corresponding colors according to the operation conditions of the color sacs, and each color corresponds to a set pressure value. The pressure sensitive film provided by the present disclosure determines a pressure range of the device according to the different colors, realizing effective monitoring of the device pressure; and determining the flatness of the device according to the evenness of the colors of tested regions, thus combining the pressure test and flatness test, so as to make the routine device pressure monitoring more convenient.

An apparatus and method for determining a temperature in a system having an object, an optical sensor, and a gas flow passing between the object and the optical sensor, sensing, with the optical sensor, a wavelength emitted from the object and indicative of an attenuation, sensing, with the optical sensor, a wavelength emitted from the object and indicative of a temperature of at least one of the object or the gas; and calculating a temperature of the gas using the wavelengths.

An apparatus and method for determining a temperature in a system having an object, an optical sensor, and a gas flow passing between the object and the optical sensor, sensing, with the optical sensor, a wavelength emitted from the object and indicative of an attenuation, sensing, with the optical sensor, a wavelength emitted from the object and indicative of a temperature of at least one of the object or the gas; and calculating a temperature of the gas using the wavelengths.

A pressure sensor includes: a light source that outputs signal light; a sensor optical fiber where the signal light is input and the signal light is propagated with a loss of 0.3 dB/m or more; and an optical receiver that receives the signal light propagated through the sensor optical fiber. Further, pressure applied to the sensor optical fiber is detected on a basis of intensity of the signal light received by the optical receiver.

A system and apparatus comprising a multi-sensor catheter for right heart and pulmonary artery catheterization is disclosed. The multi-sensor catheter comprises multi-lumen catheter tubing into which at least three optical pressure sensors, and their respective optical fibers, are inserted. The three optical pressure sensors are arranged within a distal end portion of the catheter, spaced apart lengthwise within the distal end portion for measuring pressure concurrently at each sensor location. The sensor locations are configured for placement of at least one sensor in each of the right atrium, the right ventricle and the pulmonary artery, for concurrent measurement of pressure at each sensor location. The sensor arrangement may further comprise an optical thermo-dilution sensor, and another lumen is provided for fluid injection for thermo-dilution measurements. The catheter may comprise an inflatable balloon tip and a guidewire lumen, and preferably has an outside diameter of 6 French or less.

A system and apparatus comprising a multi-sensor catheter for right heart and pulmonary artery catheterization is disclosed. The multi-sensor catheter comprises multi-lumen catheter tubing into which at least three optical pressure sensors, and their respective optical fibers, are inserted. The three optical pressure sensors are arranged within a distal end portion of the catheter, spaced apart lengthwise within the distal end portion for measuring pressure concurrently at each sensor location. The sensor locations are configured for placement of at least one sensor in each of the right atrium, the right ventricle and the pulmonary artery, for concurrent measurement of pressure at each sensor location. The sensor arrangement may further comprise an optical thermo-dilution sensor, and another lumen is provided for fluid injection for thermo-dilution measurements. The catheter may comprise an inflatable balloon tip and a guidewire lumen, and preferably has an outside diameter of 6 French or less.

A temperature correcting pressure gauge which has a diaphragm having at least one surface coupled to a source of pressure to be measured, the diaphragm first surface having a first FBG from a first optical fiber attached in an appropriately sensitive region of the diaphragm, a FBG from a second optical fiber attached to the opposite surface from the first FBG, the first and second FBGs reflecting or transmitting optical energy of decreasing or increasing wavelength, respectively, in response to an applied pressure. The first and second FBGs have nominal operating wavelength ranges that are adjacent to each other but are exclusive ranges and the FBGs also have closely matched pressure coefficients and temperature coefficients.