SU1656434A1 - Device for metal and alloy electric resistance measurement - Google Patents

Abstract

The invention relates to analytical instrumentation and can be used in laboratory and industrial conditions to determine the electrical resistance of metals and alloys and to study their resistance to temperature. The aim of the invention is to increase productivity and automate measurements. For this, the recorder is made in the form of a specialized data processing device with a control computer, and a control unit is inserted into the device for measuring the electrical resistance of metals and floorboards, which implements the heating procedure — measuring electrical characteristics followed by calculating the resistance in the computer unit. the form when generating control signals and supplying them to a controlled source of heating current, 1 sludge. (L

Description

The invention relates to an automatic instrument making and can be used in laboratory and industrial conditions to determine the electrical resistance of metals and alloys and to study the dependence of their resistance on temperature.

The purpose of the invention is to increase productivity and automate measurements.

The drawing shows a block diagram of the proposed device.

The device contains a measuring cell 1 with a primary temperature transducer 2 (PPT), terminals 3 for fixing the sample under test, control unit 4 and recorder 5. Unit 4 includes a controllable current source (BEP), two starting elements (PE) 7 and 8, counter decoder 9, decoder 10, generator 11,

counter 12, controllable key 13 and amplifier 14. The recorder contains a micro-computer 15 through an interface device 16 connected to a digital printing device (CPU) 17

The current source 6 is connected to the terminals 3 for fixing the sample under study. PPT 2 through the amplifier 14 is connected to two inputs of a micro-computer 15 whose third input is connected to a current source 6. The first PE 7 is connected through a serially connected counter decoder 9 and a decoder 10 connected to the control input of the current source 6. The generator 11 through the key-13 is connected to the first input of the counter 12, the second input of which is connected to the second output of the first PE 7, and the output of the counter 12 through the second PE 8 is connected to the exchange circuit between the micro-computer 15 and the coO device 16

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prine The second output of the counter 12 is connected to the second input of the counter-decoder 9, and the second output of the decoder 10 is connected to the control input of the key 13.

The device works as follows.

The test specimen is fixed at terminals 3. An FPT 2 is attached to the middle part of the sample, after which the cell 1 is evacuated. The microcomputer 15 introduces the program, the experiment code and the PE 8.

The device is then put into start mode.

The process of automatically applying voltage to the sample, measuring the voltage, current and temperature after reaching thermodynamic equilibrium, followed by calculating the resistance and printing results, begins. The process is regulated and controlled by the control unit 4, the mode of operation of which is determined by the generator 11, which produces a pulse of duration T.

When the PE 7 is switched to the Start mode, the pulses from the generator 11 through the key 13 are fed to the input of the counter 12, which for every 64 incoming pulses produces one pulse at the second output and three pulses at the first output. The pulse + 1 from the second output is fed to the counter decoder 9, changing its state by one. This state is decrypted by the decoder 10, which in turn controls the current source 6.

The emf of FPG 2 is fed to the amplifier 14. and then to the microcomputer 15. After establishing thermodynamic equilibrium, i.e. after a time equal to 6T, which is counted by counter 12, one pulse is fed to microcomputer 15 from the first output of counter 12 via PE 8 to start the first cycle of simultaneous measurement of voltage, current and temperature and then stop the measurements. After stopping, after a time equal to 16T, two more pulses with an interval of 16T are sent from counter 12 to the microcomputer, which transfer it to the counting mode with subsequent printing of the results to the CPU 17.

After the first cycle of measurement-count-printing from the second output of counter 12, the next pulse +1 is applied to the counter-decoder, and an additional voltage of the current source is applied to the sample, after which the measurements and calculations are repeated.

Claims (1)

Apparatus of the Invention A device for measuring the electrical resistance of metals and alloys, comprising a measuring cell with a primary temperature transducer, a current source connected to the terminals for fixing the sample under investigation, and a recorder, characterized in that it is equipped with a control unit to improve performance and automate measurements. including two starting elements, a counter, a counter-decoder, a controllable key, a generator, a decoder and an amplifier, the current source is controllable and on It is part of the control unit, the recorder contains a microcomputer connected through a digital printer through an interface device, the primary temperature converter through an amplifier connected to two inputs of a micro-computer, the third input of which is connected to a current source, the first starting element through serially connected counter-decoder and the decoder is connected to the control input of the current source, the generator is connected via a key to the first input of the meter, the second input of which is connected to the second output of the first start-up the second element is connected to the second input of the counter-decoder, and the second output of the decoder is connected to the control input of the key.