Abstract: The present invention provides an improved rupture disk apparatus and manufacturing method. The apparatus includes a rupture disk having at least one area of weakness formed by the displacement of material through a partial shearing motion. The weakened area is capable of withstanding pressure cycling because the rupture disk flange acts to support the weakened area during use. The apparatus further includes a safety member adjacent to the rupture disk on the outlet side to ensure opening, the safety member having at least one rupture-initiating, stress-concentrating point positioned to contact the rupture disk weakened area.

Abstract: By arranging a pair of an ultrasonic wave transmitting sensor and an ultrasonic wave receiving sensor in opposition across a crack in a reinforced concrete construction. An ultrasonic wave is transmitted from the ultrasonic wave transmitting sensor at a first position. A reflected wave is then received by the ultrasonic wave receiving sensor at the first position. Also, the ultrasonic wave is transmitted from the ultrasonic wave transmitting sensor at a second position. A reflected wave is then received by the ultrasonic wave receiving sensor at the second position. The received waves at two positions are provided mutual phase shift for a predetermined period and summed in reversed phase for deriving a rise time of the wave reflected from the crack.

Abstract: A transversal correlator is disclosed for demodulating a phase shift keyed (PSK) signal. The PSK signal is mixed with a local oscillator signal to produce quadrature I-channel and Q-channel signals. The I-channel and Q-channel signals are sampled at a periodic rate and the samples are propagated through a shift register for each channel. A preselected pseudo noise signal is stored in a local register which has an output tap for each stage. Each of the analog shift registers has a stage corresponding to one of the stages of the local register. Each of the I-channel and Q-channel samples is multiplied by the binary state in the corresponding stage of the local register. This multiplying operation produces a plurality of product signals. Product signals for alternate samples of the I-channel signal are summed with alternate but offset samples of the Q-channel signal to produce a first summation signal.