SU991290A1 - Device for registering acoustic emission signals - Google Patents

Description

. one

The invention relates to non-destructive testing and can be used to register acoustic emission pulses (AE when testing materials.

A device for determining the quality of products is known, which is based on the registration of AE and includes a sensor, amplifier, detector, amplitude discriminator, intensity, Q meter and counter 1 3

The drawback of the device is the low reliability of measuring the intensity of AE.

The closest in technical essence to the invention is a device for recording acoustic emission signals, including a series-connected detector. a torus and an electronic key, an amplitude 20 discriminator connected to the 5th detector, and a recorder, and a gate driver, the output of which is connected to the second input of the first one.

of the electronic rake, and the second input of the front-edge gate forcing the pulse is connected to the input of detector 2 ..

The disadvantage of this device is the large error in measuring the intensity of the AE, when the previous pulse has a smaller amplitude than the next one.

The aim of the invention is to increase the reliability of the registration of acoustic emission signals ..

Claims (2)

This goal is achieved by having a device for detecting sleep acoustic emission signals & An exponent forming unit connected between the first ametlitude discriminator and the first electronic key is sequentially connected by a second amplitude discriminator whose inputs are intended to be connected to the acoustic emission sensor and to the threshold voltage source, the second electronic key, and also the delay unit which is connected to the output of the first amplitude discriminator, and the output - to the second input of the second electronic key, and the second input of the first amplitude discriminator. n for connection to a source of threshold voltage. The drawing shows a block diagram of an apparatus for registering AE signals. The device contains a detector 1, a first electronic key 2, an exponential generator 3, a first k and a second 5 amplitude discriminators, a second electronic key 6, a pulse front pulse shaper 7, a delay block 8 and a recorder, including a counter 9 and an intensity meter 10 The device works as follows. An impulse AE arrives at the input of detector 1, is detected and arrives at the input of the first electronic key 2. At the same time, the impulse AE is applied to the second amplitude discriminator 5 and, if its amplitude is higher than the threshold voltage, arrives at the second. an electronic key 6, which starts the shaper 7 of the strobe of the front F1eont pulse. The voltage of the front-side pulse shaper 7 briefly opens the key 2, which allows the envelope of the detected pulse to flow from the output of the detector 1 to the input of the exponent-forming unit 3. In block 3, the maximum amplitude of the envelope is memorized (for example, on the capacitance) in the interval of the strobe 7 duration, which is always set much longer than the time after the sound of the sensor and the product. At the end of the gate, you generate. block 7, the input of block 3 is disconnected from the output of detector 1, and block 3 produces a voltage that drops exponentially with a constant time after the sensor and product sound and simulates the pulse envelope AE. The voltage at the output of the block, 3, is applied to the first amplitude discriminator, which generates a normalized pulse as long as the exponential; Initially, the falling voltage of block 3 does not decrease to the threshold level of discriminator A. The appearance of a normalized pulse at the output of block k closes the second electronic key b, prohibits the start of block 7. When the normalized pulse has expired, key 6 opens, the next start of the gate stator 7 is allowed, and the device returns to its original state. When the next AE pulse arrives, the operation of the device operation is repeated. Thus, the blocks entered by the s device and their operation allows to increase the reliability of recording acoustic emission by eliminating the miscalculation of the pulse, whose amplitude is smaller than the previous one. Apparatus of the Invention A device for recording acoustic emission signals comprising a series-connected detector and a first electronic key, a first amplitude discriminator connected to the detector input, and a recorder, a gate driver, the output of which is connected to the second input of the first electronic key, and a second input of the front gate generator pulse front is connected to the detector output, characterized in that, in order to increase the reliability and registration of acoustic emission signals, it is equipped with a block The formation of an exponent connected between the first amplitude discriminator and the first electronic key connected in series by the second amplitude discriminator, the inputs of which are intended to be connected to the acoustic emission sensor and the source of the threshold voltage, the second electronic key, and the delay unit whose input is connected to the output of the first amplitude discriminator, and the output is to the second input of the second electronic key, and the second input of the first amplitude disk. e; nor to the source of the threshold voltage. , Information sources. taken into account during the examination 1. Greshnikov V.A. and others. Acoustic emission. M., Publishing house of standards, 1976, p.78. . 2. USSR author's certificate No. 785753, cl. G 01 N 29/0, 1979 (prototype).