Abstract: The invention relates to a device for detecting electromagnetic radiation comprising: a resistive bolometer, a biasing circuit capable of biasing said bolometer with a predetermined bias voltage, a rejection module capable of generating a common mode current, a measuring circuit capable of being connected to a bolometer and a rejection module in order to measure the difference between the current flowing through the bolometer when it is biased and the common mode current generated by the rejection module. According to the invention, rejection module comprises: a module for estimating a current that flows through resistive bolometer when it is subjected to the bias voltage and made insensitive to the electromagnetic radiation; and a current generator which is controlled by the estimation module and generates the current estimated by the latter as a common mode current.

Abstract: The invention relates to a device for the detection of an electromagnetic radiation including: a substrate; a resistive imaging bolometer; a circuit for polarizing the bolometer at a predetermined voltage; a rejection circuit generating a common mode current, comprising a compensation bolometer thermalized in the substrate and a polarization circuit thereof; and a measuring circuit for measuring the difference between the current flowing in the imaging bolometer when it is polarized and the common mode current generated by the rejection circuit. According to the invention, the rejection circuit further comprises a current generator capable of producing a current that simulates the current induced by the self-heating of the imaging bolometer under the effect of its polarization, the sum of the current passing through the compensation bolometer and the current generated by the current generator forming the common mode current.

Abstract: A device for detecting infrared radiation including a resistive imaging bolometer, a mechanism for measuring drift in the electrical resistance of the bolometer relative to a reference value of the electrical resistance of the bolometer which corresponds to predetermined operating conditions of the bolometer, and a mechanism for correcting the effects of the drift in resistance or for correcting the drift itself.

Abstract: A device for detecting infrared radiation comprising an array of bolometric detectors which are sensitive to incident radiation and are referred to as “active” and a bolometer which is insensitive to said radiation and is referred to as “blind” formed on a substrate in which a read circuit is produced for sequentially addressing each of the rows of detectors of the array, each of the active bolometers in a single row being biased simultaneously. The read circuit also comprises means of producing a reference current (Iref) based on the blind bolometer; means of simultaneously copying the reference current (Iref) for each column of the array; and a plurality of current integrators, each associated with one column of the array and each designed to integrate the difference between the current flowing through the active bolometer of the row which is currently being read and said thus copied reference current.

Abstract: The invention relates to a device for the detection of an electromagnetic radiation including: a substrate; a resistive imaging bolometer; a circuit for polarizing the bolometer at a predetermined voltage; a rejection circuit generating a common mode current, comprising a compensation bolometer thermalized in the substrate and a polarization circuit thereof; and a measuring circuit for measuring the difference between the current flowing in the imaging bolometer when it is polarized and the common mode current generated by the rejection circuit. According to the invention, the rejection circuit further comprises a current generator capable of producing a current that simulates the current induced by the self-heating of the imaging bolometer under the effect of its polarization, the sum of the current passing through the compensation bolometer and the current generated by the current generator forming the common mode current.

Abstract: The invention relates to a device for detecting electromagnetic radiation comprising: a resistive bolometer, a biasing circuit capable of biasing said bolometer with a predetermined bias voltage, a rejection module capable of generating a common mode current, a measuring circuit capable of being connected to a bolometer and a rejection module in order to measure the difference between the current flowing through the bolometer when it is biased and the common mode current generated by the rejection module. According to the invention, rejection module comprises: a module for estimating a current that flows through resistive bolometer when it is subjected to the bias voltage and made insensitive to the electromagnetic radiation; and a current generator which is controlled by the estimation module and generates the current estimated by the latter as a common mode current.

Abstract: A device for detecting infrared radiation including a resistive imaging bolometer, a mechanism for measuring drift in the electrical resistance of the bolometer relative to a reference value of the electrical resistance of the bolometer which corresponds to predetermined operating conditions of the bolometer, and a mechanism for correcting the effects of the drift in resistance or for correcting the drift itself.

Abstract: A device for detecting electromagnetic radiation, especially infrared radiation, including an array of elementary bolometers which are sensitive to the incident radiation and are referred to as “active” bolometers and an additional row of bolometers which are substantially insensitive to the radiation and are referred to as “blind” bolometers. The active and blind bolometers are formed on a substrate in which a read circuit is produced for sequential addressing of each of the rows of the array and the row of blind bolometers, each of the bolometers in the same row being biased simultaneously. The read circuit includes a source for producing a reference current (Iref) on the basis of an additional blind bolometer which is also formed on the substrate and means of copying the reference current (Iref) to each of the columns of the array consisting of a current mirror.

Abstract: A sensor used to measure temperature or concentration of a combustible gas. The sensor includes an optical head that picks up infrared information emitted by the combustible gas. The infrared information is conveyed from the optical sensor through a diffracting device onto a strip of photodetectors. A processor receives the information garnered by the photodetectors and determines the concentration and temperature profile of the combustible gas based on a stored thermodynamic model, radiation behavior, varying the thermodynamic parameters, and comparing a calculated spectrum with the measured spectrum. The sensor additionally has elements, such as cooling devices and casing to make it suitable for use with aviation where altitude creates problems with known methods of gas temperature analysis.

Abstract: The liquid level sensor comprises a graduated tape or cable whose free end is fixed to a plunger core that includes a housing and a probe for detecting the presence of a liquid. The probe comprises a metal waveguide having a cylindrical solid top portion, a portion of smaller section constituting a mechanical amplifier, a frustoconical portion, and a cylindrical bottom end portion constituting the sensitive portion of the probe. The metal waveguide is connected to the housing of the plunger core in sealed manner via a support flange which is fixed to the conical portion of the metal waveguide in such a manner that only the portion of the waveguide situated beneath the fixing zone emerges from the housing and can come into contact with a liquid. A transducer electrically powered by electronic processing circuits is disposed at the free end of the top portion and is excited at a predetermined frequency f.sub.i to create incident elastic waves in the waveguide.

Abstract: The detector for detecting the presence of a liquid comprises: a) a metal veguide having a solid cylindrical top first portion of relatively small section with an outside diameter having a first value d1, which first portion is fixed on a support, a cylindrical rigid bottom second portion whose outside diameter has a second value d2 greater than the first value d1, which second portion extends the first portion downwards and is connected thereto by a short linking portion; b) transducer means disposed in the vicinity of the top portion of the waveguide; and c) electronic processing means. The value of the frequency at which the transducer means are excited is selected in such a manner that acoustic wave trains propagate in the cylindrical first portion at the group velocity of low frequency waves, and propagate in the cylindrical second portion at the minimum group velocity corresponding to the point of inflection in the curve of phase velocity as a function of frequency.