摘要:
Various exemplary embodiments relate to a device to measure carbon dioxide (CO2) levels, including a first oscillator group comprising a first sensor to measure air pressure, where the first sensor comprises a first sealed membrane, and where the first sealed membrane overlays a sealed first cavity; a second oscillator group including a second sensor to measure the resonance frequency of a second unsealed oscillating membrane, and where the second unsealed membrane overlays a second cavity in contact with the air outside of the second sensor; and a mixer accepting as input a first frequency measurement output from the first oscillator group and a second frequency measurement output from the second oscillator group, outputting the difference of the first frequency measurement and the second frequency measurement, and computing a carbon dioxide measurement based on the difference.
摘要:
A resonant pressure sensor including one or more resonant-type strain gauges arranged on a diaphragm may include a sensor substrate made of silicon and including one surface on which one or more resonant-type strain gauge elements are arranged and the other surface which is polished to have a thickness corresponding to the diaphragm, a base substrate made of silicon and including one surface directly bonded with the other surface of the sensor substrate, a concave portion formed in a portion of the base substrate bonding with the sensor substrate, substantially forming the diaphragm in the sensor substrate, and including a predetermined gap that does not restrict a movable range of the diaphragm due to foreign substances and suppresses vibration of the diaphragm excited by vibration of the resonant-type strain gauge elements, one or more conducting holes, and a fluid.
摘要:
The invention concerns a pressure sensor including: a micro-electromechanical vibrating device, comprising a silicon substrate (15') onto which a multilayer vibrating assembly (321) is formed; a control device (21') of said assembly in order to make it oscillate relative to said substrate at the resonance frequency or at another known frequency; and a detector for detecting the actual frequency and/or amplitude of said oscillation. Since said actual frequency and/or amplitude are affected by the conditions, in particular the pressure, of the external environment, the variations of said frequency and said amplitude with respect to the values set by said control device can be used to measure pressure variations in the surrounding environment.
摘要:
A micro mechanical backscatter sensor is provided. The backscatter sensor comprises a receiver, a transmitter and a resonator having a resonance frequency of vibration and being arranged such that an external force applied thereto alters the resonance frequency of vibration thereof. The sensor also comprises a capacitive element. Each of the receiver, the transmitter, the resonator and the capacitive element are arranged to be operatively connected to one another. The capacitor is arranged such that a voltage is generated across the capacitor in response to a received signal, said voltage causing the resonator to resonate at the resonance frequency thereof. The transmitter is arranged to transmit a signal of a frequency corresponding to the resonance frequency of the resonator
摘要:
A resonant microbeam pressure sensor is disclosed, comprising a microbeam suspended in a diaphragm in at least one point by suspension elements. Pressure applied to the diaphragm will cause the resonance frequency of the beam to shift. This shift is detectable and proportional to the pressure. The device is manufactured by surface micromachining.
摘要:
Die Erfindung bezieht sich auf eine Meßanordnung zum Messen des Luftdrucks mit Hilfe eines zu Eigenschwingungen anregbaren Drucksensors. Um den nicht vernachlässigbaren Einfluß der relativen Feuchtigkeit der hinsichtlich des Druckes zu messenden Luft zu eliminieren, wird vorgeschlagen, einen Feuchtesensor, vorzugsweise in Form eines Kondensators mit einem feuchteempfindlichen Polymer als Dieelektrikum einzusetzen und die ermittelten Druckwerte um den Einfluß der Feuchtigkeit zu bereinigen.
摘要:
This document discusses, among other things, an apparatus including a silicon die including a vibratory diaphragm, the die having a silicon die top opposite a silicon die bottom, with a top silicon die port extending from the silicon die top through the silicon die to a top of the vibratory diaphragm, and with a bottom silicon die port extending from the silicon die bottom to a bottom of the vibratory diaphragm, wherein the bottom silicon die port has a cross sectional area that is larger than a cross-sectional area of the top silicon die port, a capacitor electrode disposed along a bottom of the silicon die, across the bottom silicon die port, the capacitor electrode including a first signal generation portion that is coextensive with the top silicon die port, and a second signal generation portion surrounding the first portion.