US 4,623,030 A · Piezoelectric ratio weighing device

Abstract

A piezoelectric device is used to determine a ratio of a second weight with an original weight where the second weight is less than the original weight. A piezoelectric driver is resiliently attached to a base that is isolated from vibrations. A piezoelectric receiver and a reed are resiliently attached to the piezoelectric driver so that (1) the read is moved in response to motion of the piezoelectric driver, and (2) the piezoelectric receiver gives an electric signal out proportional to motion of the system. The entire system is set to operate on the leading edge of the resonant frequency for the system. By applying an oscillating sine wave voltage, such as 140 hertz, to the piezoelectric driver, and by applying an unknown mass to the tip of the reed, a first output is obtained from the piezoelectric receiver which represents the original weight. Next by removing part of the mass by any convenient means, such as heat, a second output is obtained that represents the second weight. By a ratio of the second output/first output (or a signal equivalent to the weights being measured), the percent of the mass remaining is determined.

Claims38

Dependent claims

A device for determining a ratio by weight of a first sample to a second sample comprising:

a base;
a piezoelectric driver anchored by a first part thereof to said base;
means for supplying an AC voltage to said piezoelectric driver to cause a second part of said piezoelectric driver to vibrate upon receiving said AC voltage;
a piezoelectric receiver mechanically linked to, but electrically isolated from, said piezoelectric driver to transmit vibrations from said piezoelectric driver to said piezoelectric receiver;
means for applying, directly or indirectly, said first sample or said second sample to receive said vibrations from said piezoelectric driver, said first sample or said second sample vibrating with said piezoelectric driver;
means for receiving output signals from said piezoelectric receiver, said output signals being representative of said vibrations transmitted from said piezoelectric driver;
frequency of said AC voltage from said supply means being adjusted to set overall operating frequency of said device immediately adjacent one side of a resonant frequency, thereafter said first sample being applied to said applying means to give a first output signal from piezoelectric receiver and said second sample being applied to said applying means to give a second output signal from said piezoelectric receiver, comparing said second output to said first output to give a ratio by weight of said second sample to said first sample.

4 more elements

A piezoelectric device for comparing a first signal representing a weight of a sample with a second signal for a portion of said sample for determining percent by weight of said sample remaining, said device comprising:

a base;
a piezoelectric driver anchored to, but electrically isolated from, said base;
a piezoelectric receiver mechanically linked to, but electrically isolated from, said piezoelectric driver to receive vibrations therefrom;
applying means mechanically linked to said piezoelectric driver to receive vibrations therefrom;
means for supplying AC voltage to said piezoelectric driver to cause vibrations therein, said supplying means setting frequency of said AC voltage to operate on one side of a slope of resonant frequency of said device;
means for receiving output signals from said piezoelectric receiver as vibrations are received from said piezoelectric driver, a first output signal being generated when said sample is applied to said applying means, a second output signal being generated when part of said sample is removed, a ratio of said second output signal to said first output signal giving percent by weight of said sample remaining.

3 more elements

An apparatus for determining carbon residue in a petroleum product comprising:

a base;
a piezoelectric driver with a first part being bonded to, but electrically isolated from, said base;
a piezoelectric receiver being mechanically linked to, but electrically isolated from, said piezoelectric driver to transmit vibrations therebetween;
a reed being mechanically linked on a first end to either said piezoelectric driver or said piezoelectric receiver to transmit vibrations therebetween;
generating means for applying an AC voltage to said piezoelectric driver to cause vibrations therein, said generating means setting frequency of said AC voltage to operate on a leading edge of a resonant frequency for said apparatus;
means for applying a small sample of said petroleum product to a second end of said reed, said small sample causing resonant frequency of said apparatus to shift toward said frequency of said AC voltage, said piezoelectric receiver giving a first output signal with said small sample applied to said reed;
means for heating said small sample to evaporate essentially everything except carbon residue therein, said piezoelectric receiver giving a second output signal with said carbon residue on said reed;
and
means for comparing said second output signal with said first output signal to give percent by weight of said carbon residue in said small sample.

6 more elements

Dependencies are inferred from the claim text.

Piezoelectric ratio weighing device

Life of this patent

Piezoelectric ratio weighing device

Life of this patent

Abstract

Claims38