SU962803A1 - Apparatus for measuring the arrival time gap of acoustic emission signals - Google Patents

Description

(54) DEVICE FOR MEASURING THE DIFFERENCE OF TIMES OF PARISH ACOUSTIC EMISSION SIGNALS

The invention relates to non-destructive testing and can be used in devices for determining the coordinates of developing defects by the method of acoustic emission.

A device is known for determining the difference in arrival times of acoustic emission signals containing several reception channels, a correlometer and a time interval meter D The closest in technical essence to the present invention is a device for measuring the difference in arrival times of acoustic emission signals containing m reception channels . outputs covered by a bus Reset and connected in series the first time interval shaping unit and the first time interval meter 2.

However, devices have a low speed.

The purpose of the invention is to increase speed.

This goal is achieved due to the fact that a device for measuring the difference of acoustic emission signals containing m channels of receiving signals connected to their outputs /

bus-covered Reset and the first time interval shaping unit and the first time interval meter, connected in series, are equipped with n identical nodes, each of which consists of m channels, including consecutively connected delay blocks, a trigger and a key, and connected to the outputs

10 channels covered by a common bus for a node Reset, sequentially connected blocks of forming time intervals of a node and a meter of time intervals of a node, second inputs m

15 keys of each node are connected to the outputs m of the reception channels, respectively, the outputs n of the keys of each node are connected to the inputs of the time interval shaping unit of each

The node 20, the outputs of the first time interval shaping unit are connected to the inputs m of the delay blocks of the first node, and the m outputs of the time interval shaping unit of the previous node are connected to the inputs m of the delay blocks of the next node.

The drawing shows the block diagram of the device.

The device contains m channels 1

Claims (2)

30 reception, serially connected first time interval shaping unit 2 and first meter 3 time intervals, n nodes, each of which consists of m channels formed by delays connected in series 4, trigger 5 and key b, and time intervals connected in series node and meter 8 time intervals of the node, the outputs of the channels 1 reception connected to the inputs of the keys b of each node, respectively, the outputs of the block 2 forming time intervals are connected respectively to passages 4 delay blocks of the first node, and generating unit 7 outputs time intervals previous node, Conn cheny respectively to the inputs of four delay units subsequent node. The device works as follows. Acoustic emission signals occur on the signal receiving channels 1 at different points in time. From these signals, pulses are generated, which arrive at the inputs of the first time interval shaping unit 2. It forms rectangular pulses whose duration corresponds to the time intervals between the signals in different channels. The latter are fed to the first meter of 3 time intervals, where their values are measured, for example, by a pulse-counting method, and the measurement results from the outputs are sent to the recorder. Simultaneously with the commencement of the formation of time intervals TL from the control outputs of the first unit 2, the formation of time intervals arrives at the inputs of the delay unit 4 special signals corresponding to the appearance of the generated signals at the inputs of this unit 2. These signals delay in the delay units 4 by an amount T, slightly longer than the pulse duration at the output of channel 1 for receiving signals. The received signal overturns the corresponding trigger 5, and its signal opens the corresponding normally open key b. Thus, after the occurrence of a signal in channel 1, the corresponding key 6 opens, the input of which is connected to the output of the same first channel 1. The next signal. A signal that appears in the same channel enters through the key b in the unit 1 for shaping unit T. Unit 7 generates pulses in the same way as the first time interval shaping unit 2, and meter 8 measures the aT values similarly to the first 3 time interval meter. The same signals from the outputs of channels 1 also arrive at block 3, but they are no longer reacts. Similarly, after the occurrence of the second signal in one reception channel 1, the control signal from the output of BLB 7 allows the signals to flow to the next node, where also T is measured between the next group of signals in channels 1. The recorder polls the LT meters alternately (in the direction of increasing node number ) and after recording the results, the meter d T of the corresponding node is reset. The device can measure the time intervals l T when signals appear in one channel more often than at intervals dTta on average n times (by the number of nodes). Thus, the device allows to increase the speed when measuring the difference in arrival times of acoustic emission signals. Apparatus of the Invention A device for measuring the difference in arrival times of acoustic emission signals, comprising m channels for receiving signals, connected to their outputs, covered by a Reset bus and connected in series to a first generation unit, time intervals and a first time interval meter, characterized in that, in order to increase speed , it is equipped with n identical nodes, each of which consists of m channels, including a series-connected delay block, a trigger and a key, and connected to the output channels covered by a common bus for a node; Reset of a node’s time intervals forming a node and a node’s time interval meter; second inputs m of keys of each node are connected respectively to the outputs of the receive channels, outputs of the keys of each node are connected to inputs of a block of time intervals of each node , the outputs of the first time interval shaping unit are connected respectively to the inputs m of the delay blocks of the first node, and the hp outputs of the time interval shaping unit are podklyuche.ny of node m to the inputs of delay units subsequent node. Sources of information taken into account in the examination 1.Voloshin V.I. et al. Acoustic determinant of the location of a developing defect. - Flaw detection, 1980, 8, p .. 69-74. 2. USSR author's certificate in application number 2530536, cl. QOl N 29/04 (prototype).