SU1206623A1 - Pocket scales - Google Patents

Description

The invention relates to a weighing technique and can be used, for example, for precision measurement of a person's weight.

The purpose of the invention is to increase the accuracy by providing unidirectional loading of the force sensor.

FIG. 1 shows a functional diagram of the scales; in fig. 2 shows section A-A in FIG. one.

The scales comprise a housing 1, a load receiving platform 2, a first lever including the first supporting element 3 and the first loading element 4, a second lever including the second supporting element 5 and the second loading element 6 the first 7 and the second 8 quartz resonators, between which a calibrated the gap 9, on the first 7 and second 8 quartz resonators deposited metallized zones 10, the latches 11 and 12 are mounted on the first and second levers for fixing the position of the first 4 and second 6 load elements relative to the first 3 and second 5 supporting The elements used to set the lengths of the arms of the first and second levers of the first 13 and second 14 scales serve to ensure an accurate setting of the lengths of the arms of the first and second levers, the first 15 and the second 16 measurement risks are plotted on the first 4 and second 6 load elements for counting the lengths of the arms of the first and the second levers, the first 17 and second 1B stops serve to limit the movement of the first and second levers during overloads, the first 19 and second 20 side walls serve to seal the internal volume of the housing 1. The first 21 and second 22 multivibrators are connected us sooot- respectively to the metallized areas 10 of the first 7 and second 8 quartz resonators, the outputs of which are connected to the input of the adder 23, whose output is connected to the input digital

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indicator 24, showing the magnitude of the measured mass in the digital expression (in mass units). The axis 00 is the load axis, the axis XX - 5 is the crystallographic axis (the axis of the power-frequency sensitivity).

The operation of the device is based on the direct and inverse piezoelectric effects, on the force-frequency effect of a vibrating quartz resonator on the localization of the vibrational energy in the localized zones of the quartz resonator and the linear force-to-moment transformations.

In the initial position, a power supply is supplied to the multivibrators 21 and 22, the adder 23, and the digital indicator 24, which indicates the initial value of the measured mass, O kg, from the power supply unit (not shown).

When placed on the load-receiving platform 2 of the object (or person) being measured, the first and second levers perceive a force downward 25 along the axis of the OO — which in the first quartz resonator 7 creates a tensile force and in the second quartz resonator 8 a compressive force.

Due to the effect of the force-frequency effect, the frequency of the piezoelectric oscillations in the first quartz resonator 7 decreases, and in the second quartz resonator 8 it increases.

After the summation of the electrical signals over the frequency in the adder 23, the sum of the frequency increments of the first 7 and second 8 quartz resonators is generated.

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thirty

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Thus, the total value is displayed on the digital indicator 24. the frequencies of the piezoelectric oscillations of the first and second quartz resonators corresponding to the measured object mass (with a certain conversion coefficient), since the conversion occurs according to a linear law.

FIG. g

Claims (1)

POCKET SCALES containing a body with a base and support legs, a load receiving platform kinematically connected with a piezo 1 ^{15 3} “Τι resonant force transducer connected to a digital indicator, characterized in that, in order to increase accuracy by providing unidirectional loading of the force transducer, the support posts are made in the form of kinematically interconnected at one end by means of a piezoresonant force transducer two levers, the supporting elements of which are mounted on the base of the housing, and the loading elements are installed at the other ends of the levers, are made with the possibility of a fixed movement relative to the supporting elements and kinematically connected to the load platform. ttt TO -20 '0 ~ 18 SU „1206623 // Figure 1 -> ΖΓ