A pulse echo equipment is provided for automatically impedance matching test leads. Test pulses are applied to test leads and switches 10 and 12 are selectively closed for different short periods of time. The average voltage developed during those periods is applied via a comparator 30 to allow clock pulses to be counted by a counter 34 and to vary the effective impedance of a matching circuit by supplying a current to a lamp 40. A light sensitive resistor 42 is part of the matching circuit of t...

A coin testing apparatus comprises transmitting and receiving coils on opposite sides of a coin passageway. The transmitting coil is connected to high and low frequency oscillators. In the high frequency channel the signal is amplitude controlled by a voltage controlled amplifier rectified by a rectifier and smoothed by a long time-constant circuit. The initial rise in level caused by a coin entering between the coils is detected by an instantaneous level change comparator which responds to the ...

A cigarette testing device comprises means to apply positive or negative pressure to one end of each cigarette; means defining a chamber around at least part of the cigarette, with seals around the cigarette to restrict communication between the interior of the chamber and atmosphere; and means to detect the pressure in the chamber during testing; and including means defining a predetermined deliberate leakage path between the chamber and atmosphere.

Apparatus is disclosed for monitoring the performance of a plurality of repeaters in a transmission line. Each repeater incorporates a filter tuned to a frequency individual to that repeater and first means for changing the frequency of the received signal which may introduce a frequency error. A frequency synthesizer provides a test signal at a predetermined discrete frequency, varies the frequency according to said error and provides a reference frequency signal. A phase detector is employed t...

A cigarette testing device comprises a conveyor drum which is arranged to carry cigarettes sideways through a testing station, and which includes a pair of axially spaced sets of sprocket teeth, the cigarettes being carried in the recesses between the teeth; a suction or pressure chamber which is mounted adjacent to the conveyor drum and is arranged to communicate with spaces formed between the two sets of sprocket teeth, so that at least part of each cigarette is surrounded by predetermined suc...

Testing an engine having a rotary power output shaft by mechanically-coupling the output shaft of the engine to the rotor of a rotary electrical machine, operable alternatively in motor and generator modes, by connecting output/input conductors of the machine to conductors of an electrical supply main from which electrical power will be taken by the machine, when the machine is operating in the motor mode, and to which electrical power will be supplied by the machine, when the machine is operati...

A technique for detecting faults, blockages or holes, in a duct (6). A burst of compressed gas is injected into the duct and the decay of the pressure pulse monitored by a transducer at the gas burst launch end of the duct. A reference decay pressure that would be expected for a perfect duct is generated and the monitored decay is compared with the reference decay for deviation. A perforated duct exhibits greater pressure decay and a blocked duct less pressure decay than a perfect duct. The time...

A phased array of transducers is placed in contact with a block (15) of sound absorbent material surrounded by a housing (12) in such a manner that the block and housing together define an effectively anechoic chamber. A plurality of transducer elements (20) mounted within the block (15) are driven by variable phased drive electronics so as to simulate acoustic plane waves. The receiver field sensitivity of the array is measured. Alternatively the transducers under test may be driven and the tra...

A test apparatus for data processing and/or editing test data obtained from an object unit to be tested includes, in combination, an organization trade-off element; a failure mode and effect analysis list preparation element, a design review element consisting of a learning section, a knowledge base section and an inference section; a diagnosis rule preparation element; and a data diagnosis element consisting of a knowledge data base section and an inference function section.

The residual strength of electricity poles is determined by the deflection of the poles under a pre-determined applied load. The load is applied by an extensible ram which has a foot secured to the base of the pole by a chain and a head plate with teeth which engages the sides of the poles. A preset hydraulic pressure is applied to the ram by a manual pump and the deflection if measured by strain gauges mounted on a support frame. The load deflection data are fed to a programmed computer which c...