Abstract: Systems and methods for pressure measurement are provided. A ludion with a trapped gas bubble floats between two liquids. Pressure acting upon the liquids causes the bubble to expand or contract, resulting in movement of the ludion which can be measured and correlated with pressure change. Pressure measuring device can measure pressures from 0.05 inHg to 110 inHg with a four-to-one Test Accuracy Ratio (TAR) without using mercury.

Abstract: An intake body, systems, and method for reducing acoustic resonance in pressure tap passages include determining and/or setting the length of the drilling tap passages to a value such that the natural frequency of each pressure tap passage is outside of or does not substantially overlap with operational frequency content of an air stream in the intake body. The intake body, systems and method reduce the possibility of exciting the natural acoustic frequencies of the pressure tap passages, and can lead to improved signal-to-noise ratio when detecting EGR flow using a delta-P measurement system.

Abstract: A target pressure detection device (1) includes a housing (10), a resilient membrane (12), and a pressure detection unit (14). The housing (10) forms a chamber (102) having an open end and the housing (10) forms a through hole (104). The resilient membrane (12) is mounted to the housing (10) to cover and close the open end of the housing (10) so as to set the chamber (102) in an air-tight condition. The pressure detection unit (14) is mounted to the through hole (104) and forms therein an accommodation compartment (140) that movably receives therein a floating element (142). The accommodation compartment (140) receives therein a sensor (144). The sensor (144) can effectively detect a movement of the floating element (142) and thus the precision of detection of the target can be improved through detecting change of airflow.

Abstract: A target pressure detection device (1) includes a housing (10), a resilient membrane (12), and a pressure detection unit (14). The housing (10) forms a chamber (102) having an open end and the housing (10) forms a through hole (104). The resilient membrane (12) is mounted to the housing (10) to cover and close the open end of the housing (10) so as to set the chamber (102) in an air-tight condition. The pressure detection unit (14) is mounted to the through hole (104) and forms therein an accommodation compartment (140) that movably receives therein a floating element (142). The accommodation compartment (140) receives therein a sensor (144). The sensor (144) can effectively detect a movement of the floating element (142) and thus the precision of detection of the target can be improved through detecting change of airflow.

Abstract: A combined wet-wet differential transducer and a gage pressure transducer located in the same housing, comprising a semiconductor chip which comprises a gage sensor chip on one section and a differential sensor chip on a second section. Each sensor chip has a Wheatstone bridge comprising piezoresistors and is responsive to an applied pressure. The gage chip and the differential chip are placed in a header having a front section and a back section adapted to receive a first and second pressure, respectively. The sensors are in communication with first and second pressure ports such that the absolute sensor provides an output indicative of a pressure applied to a first port and the differential sensor provides an output indicative of the pressure difference between the first and second pressure ports.

Abstract: A measuring instrument includes a first temperature sensor, a second temperature sensor and circuitry. The first and second temperature sensors each generate a signal indicative of the temperature of a medium being detected. The circuitry is configured to activate verification of temperature being sensed with the first sensor. According to one construction, the first temperature sensor comprises at least one thermocouple temperature sensor and the second temperature sensor comprises an optical temperature sensor, each sensor measuring temperature over the same range of temperature, but using a different physical phenomena. Also according to one construction, the circuitry comprises a computer configured to detect failure of one of the thermocouples by comparing temperature of the optical temperature sensor with each of the thermocouple temperature sensors. Even further, an output control signal is generated via a fuzzy inference machine and control apparatus.

Abstract: A measuring instrument includes a first temperature sensor, a second temperature sensor and circuitry. The first and second temperature sensors each generate a signal indicative of the temperature of a medium being detected. The circuitry is configured to activate verification of temperature being sensed with the first sensor. According to one construction, the first temperature sensor comprises at least one thermocouple temperature sensor and the second temperature sensor comprises an optical temperature sensor, each sensor measuring temperature over the same range of temperature, but using a different physical phenomena. Also according to one construction, the circuitry comprises a computer configured to detect failure of one of the thermocouples by comparing temperature of the optical temperature sensor with each of the thermocouple temperature sensors. Even further, an output control signal is generated via a fuzzy inference machine and control apparatus.

Abstract: An improved regulating and gauging device for attachment to tank fed breathing apparatus used in such endeavors as scuba diving or fire fighting. On the body of the device are components which concurrently function to provide the diver or other user with a single source for what are conventionally, multiple components of a pressure gauge, a regulator, and a buoyancy compensating control unit. The device has mounted in or upon the device body, a mechanical or digital display of the remaining tank pressure in the attached supply tank, and thus breathable air supply. Also provided are an outlet to a buoyancy control bag, and a quick connect air supply port for another person to use in emergencies, or as needed. Additional utility is achieved by the provision of the pressure gauge which is mounted upon the exterior buoyancy compensating control unit body where the user can easily see it during use.

Abstract: There is provided an apparatus for measuring variations in pressure including a container for housing a volume of liquid and an indicator float to be movably supported by the liquid therein. The float is to have a hollow interior portion for maintaining a volume of compressible fluid, and is vertically movable within the container. The apparatus further includes a variable buoyancy equilibrium force device for automatically offsetting buoyant forces created by the compressible fluid within the float, whereby the equilibrium force is automatically varied in response to changing buoyancy of the float corresponding to changing ambient pressures. In a preferred embodiment, the variable buoyancy equilibrium force device comprises a flexible ballast structure attached to an adjustable support above the float, and wherein excess length of the ballast collects in a ballast retainer on the upper portion of the float.

Abstract: In contact-free testing a workpiece by ultrasonic energy an interferometric method and apparatus is used to sense acoustic energy by determining the deformation of a workpiece surface while such workpiece is undergoing acoustic exploration. The surface of the workpiece is illuminated by a laser beam which is reflected thereat and reaches an optical beam splitter to produce a measuring beam portion and a reference beam portion. The measuring beam portion after reflection at a mirror is transmitted to photoelectric means, while the reference beam portion is time delayed via an optical delay path and then brought to interfere with the measuring beam portion at the photoelectric means.

Abstract: A noise dosimeter permanently records ambient noise levels over a period of ime on photographic film to provide an indication proportional to the overall sound exposure level. Impinging acoustic energy is converted to representative potentials which are transformed into representative currents. These currents drive at least one light emitting diode which irradiates an area on an unexposed photographic film. The net degree of exposure over a period of time is read out or interpreted by a densitometer. The reading, proportional to sound exposure level, provides a record from which engineers, technicians, etc. can take the proper remedial action to avoid otherwise hazardous or detectable noise levels.

Abstract: The invention provides a method, an appliance and an installation for the termination of small displacements of points on the surface of a solid body.A catadioptric covering, such as a catadioptric paint or a piece of a sheet with catadioptric properties is applied on the point of the solid body whose displacement is to be determined, and after illuminating said covering, one determines in a viewing direction different from that of the displacement the variations in the quantity of light received by a photosensitive receiver coming from an image of the said covering in the plane of which is located a knife-edge partly covered by the said image.

Abstract: A simple system is described which makes surface vibrations apparent by mechanical deviation of a light beam. The system comprises two or more U springs which are fastened to the vibrating surface and which mechanically amplify the vibrations thus creating large beam deviations from small surface vibrations that occur at mechanical resonance frequencies of the U spring system.

Abstract: Apparatus and method for the remote detection of vibrations of diffuse surfaces. A beam of coherent light incident on a vibrating diffuse surface is scattered. A photodetector sees the scattering as a time-varying intensity distribution related to the vibration frequency of the surface. The detected time-varying intensity distribution is converted into time-varying electrical currents which can be rendered audible by using a loudspeaker or visual by using an oscilloscope.

Abstract: Apparatus and method wherein a photographic plate is doubly exposed by pulsed laser illumination to record successive instants in the history of an object under consideration. The doubly exposed plate is then developed and the photograph or hologram is used to reproduce the object in full three-dimensional detail including subtle changes in the object in the form of interference fringes where the hologram is illuminated with continuous laser illumination.