An analyzer for detecting explosives has at least one source and a plurality of gamma ray detectors. An article to be analyzed is moved adjacent the source and detectors and is subjected to neutrons which generate gamma rays in any nitrogen in the article. The gamma rays are detected and analyzed to determine the nitrogen concentration within the article. In order to achieve an area of uniform detection there are a plurality of detectors equidistant both from each source and from the article to ...

Detection device for detecting movements by means of a source of light and a photo-detector, which device is provided with: (1) a pulse generator for supplying the source of light with a proportionally very large amount of energy during a very small part of the time; and (2) with a comparator, synchronized with the pulse generator, for comparing a signal received from the photo-detector with the preceding signal during the said time and for delivering a signal to a counter in case a difference i...

Disclosed is apparatus for detecting the presence of an analyte of interest in a sample, comprising an immobilised binding partner comprising a solid support and a reversibly binding receptor which is capable of binding to the analyte of interest thereby causing a measurable change in a property of the immobilised partner, and detection means for detecting the measurable change and a method for detecting the presence of an analyte of interest.

An engine misfire detector comprises an opto-electric sensor for monitoring light produced by combustion inside a cylinder. The sensor is connected to a variable gain amplifier having a gain control circuit for controlling the amplifier gain. The output of the gain control circuit is compared with a threshold in a comparator to provide a misfire detection signal. The transfer function of the gain control circuit includes an integral term.

The detection of DTMF tones is improved in a three-step process: first testing even-numbered samples; then testing odd-numbered samples, and finally testing for tone quality (time interval and frequency stability).

A method and apparatus of detecting the condition of a flame having an emf by electrically conducting the emf generated by the flame as a signal to a sensor through an electrically isolated conductor means and sensing with said sensor an electrical parameter which is measure of the emf of the flame and wherein the parameter is the ratio of the A.C. and D.C. signal levels.

A method for detection and visualization of latent fingerprints is provided and includes contacting a substrate containing a latent print thereon with a colloidal metal composition for time sufficient to allow reaction of said colloidal metal composition with said latent print, and preserving or recording the observable print. Further, the method for detection and visualization of latent fingerprints can include contacting the metal composition-latent print reaction product with a secondary meta...

A circuit arrangement for detecting an input voltage comprises an oscillator responsive to the voltage, the oscillator including a pair of transistors (8, 9) connected as an astable multivibrator, each of the transistors having a load which comprises a primary winding (16 or 17) of a current transformer (T) and a low resistance proof resistor (12 or 13). A current flows through a secondary winding (18) of the transformer the amplitude of which current is proportional to the input voltage.

A detector for atmospheric radon using a long range alpha detector as its sensing element. An electrostatic filter removes ions from ambient air, while allowing radon atoms to pass into a decay cavity. Here, radon atoms are allowed to decay, creating air ions. These air ions are drawn by a fan through a second electrostatic filter which can be activated or deactivated, and into the long range alpha detector. With the second electrostatic filter activated, no air ions are allowed to pass, and the...

A device for detecting the presence of a chemical material, such as a gas, amongst a number of incident chemical materials comprises a group of sensors having overlapping broadband selectivities in respect of the incident materials, so that each sensor responds, to a greater or smaller extent, to each of the materials. The sensor outputs are fed to a signal processor which produces, for each material, a notional vector. These vectors are compared with stored reference vectors to identify the mat...