초록 ▼

The invention relates to a process and apparatus for detecting the presence of a physical phenomenon. The apparatus comprises a sensor which is sensitive to a characteristic quantity of the phenomenon to be studied and supplies a signal which is representative of the phenomenon. An amplifier is conn

The invention relates to a process and apparatus for detecting the presence of a physical phenomenon. The apparatus comprises a sensor which is sensitive to a characteristic quantity of the phenomenon to be studied and supplies a signal which is representative of the phenomenon. An amplifier is connected to the output of the sensor and an indicator for indicating passing beyond the threshold is connected to the amplifier. A differentiating circuit differentiates the amplified signal, while a comparator compares the differentiated signal as soon as a reference potential is exceeded. A time sampling circuit fixes prealert periods as soon as the reference potential is exceeded. The invention is applicable to the detection of pollution by combustible gaseous vapors, oil slicks, firedamp, thunderstorms, defects in surface states, etc.

대표청구항 ▼

An apparatus for the detection of the presence of a physical phenomenon comprising: a sensor sensitive to a characteristic magnitude of the phenomenon to be detected and able to supply a signal representative of said phenomenon; at least one amplifier connected to the sensor output; means for indica

An apparatus for the detection of the presence of a physical phenomenon comprising: a sensor sensitive to a characteristic magnitude of the phenomenon to be detected and able to supply a signal representative of said phenomenon; at least one amplifier connected to the sensor output; means for indicating passing beyond a predetermined threshold significant for the phenomenon to be detected, said means being connected to the amplifier output; wherein the means for indicating exceeding the significant threshold comprises: a differentiating circuit connected to the amplifier output and supplying a signal which is the derivative relative to time of the signal representing the phenomenon; a comparator whose one input is connected to the output of the differentiating circuit and whose other input is raised to a prealert reference potential, said comparator being able to supply a signal for initiating the prealert as soon as the amplitude of the differentiating circuit signal exceeds the amplitude of the reference potential; a first time sampling circuit for fixing the elementary prealert periods of duration ttp of prealert sampling periods during which the reference potential is exceeded; alert display means connected to the prealert counter output for indicating the presence of an alert during time T as soon as the number Np of prealerts exceeds a predetermined number Nal, the numbers Np and Nal being whole numbers and the number Nal being selected in such a way that 1alt