SU653309A1 - Device for measuring thickness of electroplate in course of production - Google Patents

Description

The invention relates to the measurement of non-electric values and can be used to measure the thickness of the electroplated coating.

A device for continuous counter-plating of the thickness of electroplating, containing a reference and measuring overhead eddy current transducers, a master oscillator with connected to its output generator and measuring coils of the reference and measuring overhead eddy-current transducers, a witness electrode and a standard, placed between the generating and measuring coils respectively measuring and reference overhead eddy current transducers, reference transducers and measuring signals, comparing the device connected through the transducers of the reference and measuring overhead screen eddy current transducers 1.

The disadvantage of this device is the need to change the witness electrode when loading a new batch of parts into the electroplating bath, which, in turn, requires an initial compensation of the difference between the signals of the measuring and reference transducers.

The purpose of the invention is to automate the compensation when a predetermined thickness of the signal coating of the measuring overlap screen eddy current transducer is reached.

This is achieved by the fact that the meter is equipped with a switching, storage and matching devices, the switching device is connected to the matching device by its input, and the output to the memory input, the second input of which is connected to the measuring signal converter, and the memory output is connected to the input of the matching device whose output

5 connects to the comparison device.

FIG. 1 shows a block diagram of a plating meter; in fig. 2 - time diagram of the meter.

Claims (1)

The gauge of galvanic coating thickness has a master oscillator 1, to the output of which there are connected generator coils LJ, 1z reference and measuring overhead eddy-current transducers 2, 3, coaxially located with generator measuring coils Lj, C of the same converters connected respectively via converters 4, 5 reference and measurement signals to the comparison device 6, the output of which is connected to the switching device 7 connected to the input of the memory device 8, second whose input is connected to the output of the measuring signal converter 5, the output of the storage device 8 is connected via the matching device 9 to the input of the comparison device b; A reference electrode is placed into the reference transducer between the generator and measuring coils, and the witness electrode is placed into the measuring transducer between the coils 1h and Lj. The timing diagram (see Fig. 2) illustrates the operation of the proposed device. The alternating electromagnetic fields in eddy current transducers 2, 3 are excited, as in the prototype, with the aid of a master oscillator 1 supplying the generator coils L and L. These electromotive forces are coaxial with the generator measuring coils Li, L. When starting work together with the first batch of parts, an uncovered witness electrode (a thin plate, for example, made of copper or bronze foil) is loaded into the working bath between the LS and L coils of the measuring eddy current probe, and the reference eddy current probe 2 between the coils Lj, L is placed into the reference bath uncovered standard, the same plate as the electrode witness. The standard and the witness electrode shield La, 1c electromagnetic fields induced by the generator coils, reducing the emf from this. From the measuring coils ...,., ...., The signals from these coils through the converters 4 and 5 are fed to the comparison device 6 With equal thicknesses, the signals from converters 4 and 5 are equal and their difference is zero. Otherwise, this difference, caused by the variation in the thickness of the uncovered electrode, the witness and the reference, is compensated. Then, in the reference transducer, instead of the uncoated reference, a standard covered to a predetermined thickness for this batch of parts is placed, and a galvanic process is included. A mismatch signal Uc appears at the input of the comparator device 6, corresponding to the difference between the signals from the transducers 4, 5 Ui and Uj (see Fig. 2), Us C-Ui. This difference decreases as the coverage on the witness electrode increases. When a given thickness is reached at the witness electrode, the signals C and Uj are compared (at t ti) and Ui and a. ) -Uz (t,) 0. At the output of the comparing device 6, a signal appears at the end of the process Us, which through the memory device 8 enters the input of the switching device 7 and turns on the compensating signal Us (t |) equal to the incoming signal to the second input of the switching device 7 to the signal Ui (ti) from the converter 5, from (1,) U2 (t,). This signal Oz through the matching device 9 (C) is fed to the input of the matching device 6. Then the total signal at the input of the matching device 6 is equal to the sum of the signals from the converters 4, 5 and the matching device 9, U «(t,) C (t,) - u (1,) + U4 (t,). Thus, the signal U4 (t |) compensates for the signal (i) corresponding to the thickness of the coating on the witness electrode. Therefore, the difference between the signals Us: at the moment t t | at the input of the comparator, in contrast to the prototype, corresponds to the initial difference and at t 0 and the electrostatic witness is ready for the next use. When loading a new batch of parts in the electroplating bath in the time interval from t | up to 1g immediately include the electroplating process, not producing, unlike the prototype, changing the witness electrode, setting the device, i.e. excluding the operation of compensating for the difference between the thickness of the witness electrode and the standard without coating. After the start of the process of coating the second batch of parts (t ti), the difference between the signals at the input of the comparison device 6 is reduced and when t ta U "C (t3) -Ua (t3) + U (t,) 0 and the output of the comparison device 6 appears the signal at the end of the process Us, which through the memory device 8 enters the input of the switching device, switches on its output a signal Uj (t3) equal to Uj (t3). This signal through the matching device 9 is fed to the input of the comparison device 6, the total signal of which in this case and C (1h) -ig (1h) + C (1h). The signal and (ta) compensates for the signal ig (t-j) corresponding to the thickness of the coating on the witness electrode obtained in the process of coating the first and second parts. The difference between the signals U and in this case (t 0), in contrast to the prototype, at the input of the comparison device corresponds to the initial difference Uf. at t 0. Electrosurgical witness is again ready for the next use. The proposed device for monitoring the thickness of electroplating in the process of their application will allow to automate the measurement process, does not require a large number of witness electrodes, increases productivity and simplifies the measurement process by eliminating the device setup operation when loading a new batch of parts. Invention,,; Measurement of galvanic coating thickness in the course of production, containing reference and measuring overhead eddy current transducers, master oscillator with reference oscillator and measuring overhead screen eddy current transducers connected to its output, placed between generator and measuring coils respectively measuring and reference overhead screen eddy current transducers, the reference and measuring signals, a comparator connected through inverters etalo t-GR 11Shyo1da ShbnoTUsygnal6vsootvetstvenno to the measuring coils of the reference and the measuring overhead screen vihretOkbvgh converters, characterized in that, for the purpose of automatic compensation when the predetermined signal is the coating thickness measuring overlay screen eddy current transducer, it is provided with a switching , storage and matching devices, switching device by its input but to the comparing device, and the output to the memory input, the second input of which is connected to the measuring signal converter, and the memory output is connected to the input of the matching device, the output of which is connected to the comparing device. Sources of information taken into account in the examination 1. USSR author's certificate M 326254, M. class. C 25 D 21/2, 06/22/69. L R one .L fflv -1 ,. ..- :, J.:-. -. .. ,: .one; ; 4 & o: -Ti-tr-: - ii