A temporary or portable electrical distribution system includes a distribution box supplied with power by a flexible cable. Field repairs carelessly made or other causes may result in wires being transposed or open. To eliminate hazards and to ensure proper operation of equipment, sensing means including simple circuitry in the distribution box prevents operation of a master box switch except upon the verification of proper wiring.

To supervise the integrity of an enclosed space one terminal of an ultrasonic transmission link is placed inside the space, and the other terminal outside, so that any breach of the walls enclosing the space causes an increase in the received ultrasonic intensity which initiates an alarm. The frequency used may be as low as 18 kHz. In an installation involving several supervised spaces, each space contains a receiver and a plurality of transmitters are outside all the spaces. Individual transmit...

A system for monitoring the integrity of a cable, for example a cable for towing a variable depth sonar body through the ocean, is described. Such a cable comprises a core of electrical wires surrounded by load bearing wires which are secured to the sonar body through a terminator. For various reasons cracks can appear in the load bearing wires and in extreme cases one or more of the wires may break. The monitoring system includes a transducer located near the terminator where the wires are most...

An apparatus to monitor a circuit in which an AC voltage source is connected to a plurality of paralleled current consuming loads, such as heaters, including a reactive load in parallel with the current consuming loads at a point in the circuit more distant from the voltage source than any of the current consuming loads being monitored, a phase shift detector connected to the current consuming loads and at a point in the circuit between the voltage source and the nearest current consuming load b...

A container closure integrity indicator having a first component comprised of a sheet of absorbent material permeated with an indicator dye in solution with a volatile solvent, and a second component comprised of a sheet of absorbent material permeated with a volatile activator solution, with preferably has a pH outside of the range of 5-7. The two components initially are sealed together, between a closed container surface and a superposed transparent cap member, so that the resulting liquid ph...

An electrode for use in cutting or gouging workpieces underwater by means of an electric arc comprising a generally elongated porous substrate, with a circumferential recess proximate one end to form a snap-off end on the substrate. The substrate is covered with a combined electrical insulating and waterproof coating except for a portion of the end opposite the recess which is inserted into a suitable underwater torch. When the electrode is submerged it has complete waterproof integrity until th...

The present invention is a method and apparatus for testing filled containers. The apparatus includes both a vacuum sensor and displacement sensors in combination. A computer is utilized to analyze the data from both the vacuum sensor and the displacement sensors, and based on preselected criteria, determines the seal integrity for the container.

The integrity of the insulation of an electrical device composed of at least two conductive members having a potential therebetween and at least two insulating layers successively surrounding the conductive members, is monitored by interposing an electrically conductive, integrity monitoring layer between the two insulating layers so that a first one of the insulating layers is disposed between the conductive members and the conductive layer and a second one of the insulating layers is disposed ...

A method for enhancing the security of instant lottery tickets. A book number indicating from which packet a particular lottery ticket originated is printed on the back of the ticket and an integrity number is printed on the front of the ticket. The integrity number is related to the book number by an algorithm known only to the ticket manufacturer and the lottery administration. To further enhance the security of the ticket, the book number and integrity number are simultaneously printed onto t...

A computer system includes at least on error detecting circuit for checking data bits and an associated check bit to verify that the data does not contain an error. An apparatus for verifying the operation of the error detection circuit comprises a generator unit operatively connected to said data lines for receiving data bits, for outputtting a verification signal and a check bit signal. The verification signal indicates the validity of the data bits during a read operation, and the check bit s...