sapphire crystals are widely used in various industries due to its optical, chemical and strength characteristics. When growing crystals of a lot of attention is paid to control the weight of the growing crystal. Weight data used in the control algorithms and the crystal growth of their reliability depends on the quality of the resulting product.

The problem or task

When you automate sapphire crystal growth process was a problem of measuring the weight of the growing crystal with an accuracy of no more than 100, the weighing system should perform the following functions: Set tare weighing crystal and display graphics of the current weight calibration.


To solve this problem, a system for collecting and processing data of a strain gauge weight sensor was created. The sensor used for weighing is based on a bridge circuit and requires an excitation voltage for its operation. At the output of the sensor, a voltage is formed, the value of which is proportional to the weight of the crystal. Data from the weight sensor is digitized using the ICP DAS module and transferred to the controller via USB protocol. In the controller, the data is converted into crystal weight values ​​that are output to the operator panel and used in the growth control program. The software was created in the NI LabVIEW programming environment. The program worked on the industrial controller National Instruments. As a result of the work, a weighing system was created on the basis of the existing weight sensor, which solved the problem of weighing a growing crystal and which was easily integrated into an automated system for controlling the growth of a leucosapphire crystal.


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