A detecting mechanism in a film magazine spooling machine for detecting a missing end cap of a film magazine. The detecting mechanism comprises a pusher element movable a predetermined distance into engagement with one end of the magazine film spool and to apply pressure thereto. If the end cap is properly staked on the magazine, the film spool and pusher element is stopped thereby without interferring with the normal sequence of machine functions. However, if an end cap is missing from or impro...

The presence and size of a recorded disc on a turntable is detected and indicated by the interruption of a beam or beams of energy which passes in the plane of the disc, through a hole or holes in a turntable, or beneath the turntable.

In some radio communication systems, a tone of selected frequency (usually below the voice frequency) is transmitted so as to activate only selected radio receivers in the system. Each of such radio receivers is provided with a circuit for detecting a selected tone frequency. The detecting circuit includes means for producing sequences of pulses at a rate N times higher than the selected tone frequency, so that each sequence contains one through N numbered pulses for each cycle of tone. A select...

A method is described for determining the presence of an antigen-specific antibody in a vertebrate. Effluvial tissue is exposed to antigens from known sources and is subsequently examined to detect the presence or absence of a conjugate compound formed between a particular antigen and an antibody constituent of the tissue sample. The antigen may be labeled with a fluorescent or radioactive moiety to assist in the detection of conjugate compound formation.

Apparatus and methods are disclosed for detecting a particular gas occurring at any point along a path through a given environment. A tubing having a wall through which the particular gas readily permeates is provided for placement along the path of interest. This tubing is structured so that the particular gas can enter the tubing only by permeating the tubing wall. Detection of the gas and the approximate location of permeation is achieved by withdrawing gases from within the tubing while moni...

A disposable indicator is disclosed which is useful for the measurement of substances, e.g., glucose, in biological fluids. The instrument registers the concentration of substance in a given biological fluid with indicia which are directly readable in a convenient notation system (e.g., digital or other symbolic notation). The indicator comprises an improvement over prior art disposable devices which require a comparison of the viewable indication with a color intensity scale to translate the in...

A position detecting system includes a sending unit in the form of a continuous conductor describing a Greek key pattern surrounded by a return-path conductor arrangement. The return-path conductor is so arranged as to provide additional legs of the pattern with the widths and spacings of such additional legs with respect to adjacent legs of the pattern being such as to assure a magnetic effect producing well defined and evenly spaced node and antinode signals in an associated pick-up head.

State detecting apparatus comprising: first, second and third terminals, first and second potential detecting circuits each having an input and an output, a resistance, means connecting the inputs of the first and second potential detecting circuits to the first terminal, means connecting the resistance between the first terminal and a power source, means connecting the output of the first potential detecting circuit to the second terminal, means connecting the output of the second potential det...

A zero-crossing detecting circuit where the input signal is applied to positive and negative threshold circuits. Each threshold circuit is connected to the input of a respective one-shot circuit which responds to the beginning edge of each output signal from its threshold circuit. The output pulses of both one-shots are applied to a NOR circuit which thereby responds to the beginning edges but not the trailing edges of the signals from the threshold circuits. Accordingly, variations in the trail...

There is provided a digital acceleration detecting system for rotating bodies comprising a first counter for counting the number of pulse signals corresponding to the rotational speed of a rotating body, a second counter for counting the number of the pulse signals later than the first counter, and a control circuit for generating an output signal corresponding to the difference between the counts of the first and second counters.