SU468176A1 - Digital average frequency meter - Google Patents

Description

one

The invention relates to automation and computing technology and is intended for 1 Application in radioisotope coating thickness gauges using discrete methods: information processing, and 5 can also be used in other areas of electrical and non-electrical measurement, where measurements are made by processing discrete information.

A digital measurer of the average frequency of the beta coating thickness gauge is known, which contains a counter of measurement time for the states from the preliminary measurement block; Counting and four decade counting with previous. (set using software switch; 15 switch, the output of which is connected to the first input of the control trigger, the second input of which is connected to the Start button, the main pulse counter with preset using the software switch, the first 20 and second I circuits. The outputs of the last are connected respectively, with the input of the measurement time counter and via the preliminary conversion unit - with the input of the main I pulse counter, the first inputs of which, 25

connected to the first output of the trigger control, the second inputs to the inputs of the control trigger, the second output of which is connected to the inputs of the entire meter, for example, to the output of the master oscillator and the output of the sensor.

However, the known digital average frequency meter of a beta thickness gauge of coatings has a complex graduation, produced so that the measurement result corresponds to the coating thickness of the measurement object in micrometers. In this case, the measurement time I entered into the timer is determined by the operator using known formulas. ; The purpose of the invention is the expansion of functional capabilities and the creation of meters that not only measure the average frequency of the pulses, but also ensure the implementation of mathematical operations, which greatly facilitates the work of the operator, for example, when using measurement in radioisotope coating thickness gauges.

For this, the digital meter is equipped with a switching unit, trigger and circuit

NAND, the output which is connected to the preset switch at the main counter, and the first input to the first input of the trigger and through the switching unit to the output of the preliminary counter, the second input of the NAND circuit is connected to the ground bus through the switching unit and the third input , through the trigger on the second input is connected to the input of the main counter and through the switching unit to the input of the memory unit, while the output of one of the AND circuits through the switching unit is connected to the input of the measuring time counter.

The drawing shows a block diagram of a digital average frequency meter.

It contains a measurement time counter 1 with preset switches 2., a control unit 3, a start button 4, a main counter 5 with preset switches 6, a memory block 7 with indication, the first 8 and second 9 circuits AND, the pre-counter 10, trigger 11 , AND-NOT circuit 12 and switching device 13.

Digital average frequency meter works as follows.

When the Start button 4 is pressed by the control unit 3, using the preset switches 2 and 6, in the measurement time counter 1 and the main counter 5, in the reverse code, numbers corresponding to the measurement time and the background value of the pulses from the base are entered. Next, the control unit 3 opens the AND 8 and 9 circuit and the pulses from the first input, which set the measurement time, for example, from a crystal oscillator, are received through the AND 8 circuit directly or through an additional preliminary pulse counter (not shown) to the input of the measurement time counter 1, and the pulses from the second input through the circuit AND and the preliminary pulse counter 10 are fed to the main counter 5, which after deducting the background value of the pulses will be in the initial state. Upon expiration of the measurement time, the control unit 3 is activated, which closes the circuits AND 8 and 9 and rewrites the result from the main counter 5 into the memory block 7.

In this way, the device works in measuring the average frequency when the switching device is in the first position. If the switching device 13 is in the second position, then when you press the Start 4 button, the numbers dialed on the switches 2 and the control unit 3 opens AND 8 in the measurement time counter and the main counter 5.

Pulses from the first input (in this case, a special generator can be used) through the circuit AND 8 directly or through an additional preliminary counter (not shown in the diagram) are fed to the input of the measurement time counter 1 and directly to the input of the main counter 5. After counting the number set on the switch x 6 number pulse from the output of the main counter 5 throws

trigger 11, which opens the AND-NOT scheme; 12, and the next input pulse through: the AND-NOT circuit 12 again enters the code set on the 6-digit switches into the main counter. Thus, the main counter 5 is turned into a counter with a coefficient; The conversion cost is equal to the number set-. I, on the switch x 6, Since the output of the main counter 5 is connected to the counting

the input of the memory device 7, after calculating by the counter the measurement time 1 of the number of pulses installed on the switches of preset 2 and the subsequent operation of the control unit 3 locking the AND 8 circuit, the result of dividing the number set on the switch x 2 (taking into account the discharge, if a preliminary pulse counter is used), by the number set

on switch 6.

If the switching device 13 is in the third position, then when the Start button 4 is pressed, the measurement time counter 1 and the main counter 5 are entered into

the numbers dialed on switches x 2 and 6, the control unit 3 opens the AND 8 circuit. j The pulses from the first input are fed through the AND 8 circuit to the input of the main counter 5 and the counting input of the memory block 7, when

In this case, the main counter 5 is converted into a counter with a conversion factor equal to the number set on the switches 6.

Since the output of the main counter 5 is connected to the input of the time counter, the

1, the output pulses of the main counter 5 are recalculated by a factor equal to the number set in the switches 2. Thus, when the control unit 3 triggers the locking circuit

And 8, in the memory block 7 a number will be written equal to the product of the numbers set on the switches 2 and 6.;

A digital meter provides a measurement of the measurement time required to calibrate a radioisotope coating thickness gauge by sequential

using it in the modes of measuring the average frequency, division and multiplication.

By increasing the positions of the switching device, the proposed meter can also work in the modes of addition and subtraction.

Subject invention

A digital average frequency meter containing two circuits AND, a pre-counter, a measurement time counter with a preset switch, a control unit, a main counter with a preset switch, and a memory block, characterized in that, in order to expand

functionality, it is equipped with a switching unit, a trigger and an NAND circuit, the output of which is connected to the preset switch of the main counter, and

the first input - with the first input of the trigger and through the switching unit - with the output of the preliminary counter; the second input of the NAND circuit through the switching unit is connected

the Earth bus, and the third input through the trigger on the second input is connected to the input of the main counter, and through the switching unit to the input of the memory unit, and the output of one of the AND schemes through the switching unit

connected to the input of the time meter variable.