Abstract: A data display apparatus and data display method for displaying relationships between sets of data are described. Sets of data and similarity values representing similarities between the sets of data are received, and a display is controlled to display representations for the sets of data separated in accordance with the similarity values and so as to display, in a first style, links between representations which correspond to sets of data having a strong similarity value and, in a second style, links between the representations which correspond to sets of data having a weak similarity value.

Abstract: For identifying one of a plurality of known gases in a gaseous mixture ba on air a single catalytic transducer is placed in the gaseous medium. The catalytic transducer is heated to a lower threshold temperature at which the oxidizable gas is oxidized little or not at all and a first value of a parameter characteristic of the thermal state of the transducer is captured. The catalytic transducer is then heated to an upper threshold temperature at which the oxidizable gas oxidizes significantly in contact with the catalytic transducer and a second value of the parameter characteristic of the thermal state of the transducer is captured. Using a predetermined law, a response signal representative of the gaseous medium is produced from the difference between the second and first values of the parameter characteristic of the thermal state of the catalytic transducer. The catalytic transducer is allowed to cool below the lower threshold temperature and the above operations are repeated cyclically.

Abstract: A power circuit comprises a current amplifier circuit connected between a minimum potential line and a maximum potential line. It further comprises, connected between these lines together with the aforementioned main circuit, a protection circuit which has a control input. A trigger and distributor circuit is connected in parallel with these circuits and is adapted to neutralize the protection circuit, via its control input, when the voltage across the main circuit is below a threshold value. Is it also adapted to activate the protection circuit when the voltage across the main circuit reaches this threshold value, while maintaining the voltage across the main circuit at an approximately constant ratio to the voltage between the two potential lines. The circuit is applicable in particular to controling failsafe alarm circuits, by means of logic signals, for example.

Abstract: A process of remote transmission of signals issued by at least one sensor over a transmission line, wherein the power necessary to supply the sensor is transmitted by that line in the form of an alternating current signal of approximately constant intensity, and wherein the line fulfills the triple function of supplying power to that sensor, of transmitting interrogation signals from a central station to that sensor and of transmitting data signals in response to that interrogation signal from the sensor to the central station. A device for incorporating this process is also disclosed.

Abstract: A two stage process for interrogating a detector of the concentration of combustible gas in an atmosphere. In a first stage, the detector is supplied with a low voltage and the supply is cut and an optional alarm is sounded if a positive signal has been detected. In a second stage, if the signal detected in the first stage is negative or zero, then the detector is supplied with a second, higher voltage. The signal is compared to a predetermined range and, if not within that range, an optional alarm is sounded. A device to apply the process comprising a detector, an amplifier of the signal issued by the detector, a voltage reducing circuit, and a switch that controls the voltage reducing circuit slaved by a discriminator to the sign and/or to the maximum amplitude of the signal output by the amplifier. Application of the process and device to the detection of the concentration of methane.

Abstract: A measuring cell having a measuring filament and a reference filament is disposed in a cap of sintered metal. A time base circuit, actuated by the closing of a switch, connects the filaments to an electrical supply circuit after a predetermined delay. Subsequently, the time base circuit sequentially triggers the connection of the filaments to a measuring circuit, the storage in a memory of the value of the output signal of the measuring circuit and the display of this stored value, the disconnection of the supply circuit, and the illumination of an end of operation warning lamp. The value displayed is proportional to the amount of a constituent of an atmosphere diffused into the measuring cell. The apparatus can be used as a portable fire damp meter or explosimeter.