Digital reading moisture tester

Claim 2

An electrical signal frequency measuring circuit for translating the frequency of an applied signal representative of a measured parameter into a direct reading of that parameter wherein the relationship between the applied signal frequency and the measured parameter may vary in a known manner comprising: timer means for generating a characteristic electrical signal of predetermined period; control means for electrically controlling the duration of said period; indicating means coupled to said timer means for counting the number of cycles of said applied signal occurring during said predeterined period; period altering means coupled to said control means for altering said period in accord with variations in the relationship between said applied signal frequency and said measured parameter; recycle means for causing said timer means to periodically generate said characteristic signal of predetermined duration; balance means coupled to said indicating means and said period controlling means for adjusting the length of said predetermined period to achieve a given count in said indicating means at the end of said period; and means for alternately enabling and disabling said balance means.

Claim 3

An impedance measuring circuit wherein the measured impedance is related in a known but variable way to a physical parameter and said circuit gives a direct reading of the physical parameter and comprising: timer means for generating a characteristic electrical signal of predetermined period; control means for electrically controlling the duration of said period; oscillator means including said impedance as a frequency determining element; indicating means coupled to said timer means and said oscillator for counting the number of cycles of said oscillator occurring during said predetermined period; period altering means coupled to said control means for altering said period in accord with variations in the relation between said measured impedance and said physical parameter; recycle means for causing said timer means to periodically generate said charateristic signal of predetermined duration; balance means coupled to said indicating mEans and said period controlling means for adjusting the length of said predetermined period to achieve a given count in said indicating means at the end of said period; and means for alternately enabling and disabling said balance means.

Claim 4

An impedance measuring circuit wherein the measured impedance is related in a known but variable way to a physical parameter and said circuit gives a direct reading of the physical parameter and comprising: timer means for generating a characteristic electrical signal of predetermined period; control means for electrically controlling the duration of said period; oscillator means including said impedance as a frequency determining element; indicating means coupled to said timer means and said oscillator for counting the number of cycles of said oscillator occurring during said predetermined period; period altering means coupled to said control means for altering said period in accord with variations in the relation between said measured impedance and said physical parameter; recycle means for causing said timer means to periodically generate said charateristic signal of predetermined duration; balance means coupled to said indicating mEans and said period controlling means for adjusting the length of said predetermined period to achieve a given count in said indicating means at the end of said period; and means for alternately enabling and disabling said balance means.

Claim 5

A moisture tester operative to determine the moisture content of the material under test by measuring one of the electrical properties of said material and including provisions for measuring the moisture content of different materials having a plurality of relationships between moisture content and said measured electrical property comprising: a cell for receiving an amount of the material to be tested; an oscillator including said cell as a frequency determining element thereof; means for generating an electrical signal having a period of predetermined duration; means for indicating the number of cycles generated by said oscillator during said period; means for controlling the duration of said period; and material selection means coupled to said period controlling means for altering said period in accord with the nature of the particular relationship between moisture content and said measured electrical property for the particular material under test.

Claim 6

A moisture tester operative to determine the moisture content of the material under test by measuring one of the electrical properties of said material and including provisions for measuring the moisture content of different materials having a plurality of relationships between moisture content and said measured electrical property comprising: a cell for receiving an amount of the material to be tested; an oscillator including said cell as a frequency determining element thereof; means for generating an electrical signal having a period of predetermined duration; means for indicating the number of cycles generated by said oscillator during said period; means for controlling the duration of said period; and material selection means coupled to said period controlling means for altering said period in accord with the nature of the particular relationship between moisture content and said measured electrical property for the particular material under test.

Claim 7

The moisture tester of claim 3 wherein said material selection means is comprised of slope selection means for altering said period in accord with the slope of a linear approximation of the particular relationship between moisture content and said measured electrical property for the material under test.

Claim 8

The moisture tester of claim 3 wherein said material selection means is comprised of intercept selection means for altering said period in accord with the intercept of a linear approximation of the particular relationship between moisture content and said measured electrical property for the material under test.

Claim 9

The moisture tester of claim 3 further comprising nonlinear correction means for altering said period by an amount related to the frequency of operation of said oscillator.

Claim 10

The moisture tester of claim 6 wherein said material selection means is comprised of curvature selection means for adjusting the magnitude of the period alteration created by said nonlinear correction means.

Claim 11

A moisture tester operative to determine the moisture content of the material under test by measuring one of the electrical properties of said material and comprising: a cell for receiving an amount of the material to be tested; an oscillator including said cell as a frequency determining element thereof; means for generating an electrical signal having a period of predetermined duration; means for indicating the number of cycles generated by said oscillator during said period; means for controlling the duration of said period; means for causing said generating means to periodically generate said signal of predetermined duration; balance means coupled to said indicating means and said period controlling means for adjusting the duration of said predetermined period to achieve a given indication on said indicating means at the termination of said signal establishing a reference operating condition for said tester; and means for alternately enabling and disabling said balance means.

Claim 12

A moisture tester operative to determine the moisture content of the material under test by measuring one of the electrical properties of said material and comprising: a cell for receiving an amount of the material to be tested; an oscillator including said cell as a frequency determining element thereof; means for generating an electrical signal having a period of predetermined duration; means for indicating the number of cycles generated by said oscillator during said period; means for controlling the duration of said period; means for causing said generating means to periodically generate said signal of predetermined duration; balance means coupled to said indicating means and said period controlling means for adjusting the duration of said predetermined period to achieve a given indication on said indicating means at the termination of said signal establishing a reference operating condition for said tester; and means for alternately enabling and disabling said balance means.

Claim 13

A grain moisture tester operative to determine the moisture content of a plurality of different types of grain by measuring the dielectric constant of the grain under test and comprising: a capacitive cell for receiving an amount of the grain to be tested; an oscillator including said cell as a frequency determining element thereof; timer means for generating an electrical signal having a period of predetermined duration; gate means coupled to the output of said timer means and said oscillator and passing the output of said oscillator only during the presence of said timer signal; counter means coupled to the output of said gate means for indicating the number of cycles of said oscillator Occurring during said timer signal; means for controlling the duration of said timer signal period; and grain selection means coupled to said period controlling means for altering said period in accord with the nature of the particular relationship between moisture content and dielectric constant for the grain under test.

Claim 14

A grain moisture tester operative to determine the moisture content of a plurality of different types of grain by measuring the dielectric constant of the grain under test and comprising: a capacitive cell for receiving an amount of the grain to be tested; an oscillator including said cell as a frequency determining element thereof; timer means for generating an electrical signal having a period of predetermined duration; gate means coupled to the output of said timer means and said oscillator and passing the output of said oscillator only during the presence of said timer signal; counter means coupled to the output of said gate means for indicating the number of cycles of said oscillator Occurring during said timer signal; means for controlling the duration of said timer signal period; and grain selection means coupled to said period controlling means for altering said period in accord with the nature of the particular relationship between moisture content and dielectric constant for the grain under test.

Claim 15

The grain moisture tester of claim 9 wherein said grain selection means is comprised of slope selection means for altering said period in accord with the slope of a linear approximation to the particular relationship between moisture content and dielectric constant for the grain under test.

Claim 16

The moisture tester of claim 9 wherein said grain selection means is comprised of intercept selection means for altering said period in accord with the intercept of a linear approximation to the particular relationship between moisture content and dielectric constant for the material under test.

Claim 17

The moisture tester of claim 9 further comprising nonlinear correction means coupled to said period controlling means for altering said period by an amount related to the frequency of operation of said oscillator.

Claim 18

The moisture tester of claim 12 wherein said grain selection means is comprised of curvature selection means for adjusting the magnitude of the period alteration caused by said nonlinear correction means.

Claim 19

The grain moisture tester of claim 9 further comprising temperature correction means coupled to said timer period controlling means for altering said period by an amount related to the temperature of the grain being tested.

Claim 20

The grain moisture tester of claim 9 wherein said temperature correction means comprises a ribbon thermocouple couple disposed within said capacitive cell and operatively coupled to said timer means for altering the duration of said period.

Claim 21

A grain moisture tester operative to determine the moisture content of the grain under test by measuring the dielectric constant of said grain and comprising: a capacitive cell for receiving an amount of the grain to be tested; an oscillator including said cell as a frequency determining element thereof; timer means for generating an electrical signal having a period of predetermined duration; gate means coupled to the output of said timer means and said oscillator and passing the output of said oscillator only during the presence of said timer signal; counter means coupled to the output of said gate means for indicating the number of cycles of said oscillator occurring during said timer signal; means for controlling the duration of said timer signal period; recycling means for periodically actuating said timer means; balance means coupled to said counter means and said period controlling means and responsive to the indication given on said counter means at the end of each timer period to adjust said timer period to achieve a given indication at the end of each timer period; and means for alternately enabling and disabling said balance means.

Claim 22

A grain moisture tester operative to determine the moisture content of the grain under test by measuring the dielectric constant of said grain and comprising: a capacitive cell for receiving an amount of the grain to be tested; an oscillator including said cell as a frequency determining element thereof; timer means for generating an electrical signal having a period of predetermined duration; gate means coupled to the output of said timer means and said oscillator and passing the output of said oscillator only during the presence of said timer signal; counter means coupled to the output of said gate means for indicating the number of cycles of said oscillator occurring during said timer signal; means for controlling the duration of said timer signal period; recycling means for periodically actuating said timer means; balance means coupled to said counter means and said period controlling means and responsive to the indication given on said counter means at the end of each timer period to adjust said timer period to achieve a given indication at the end of each timer period; and means for alternately enabling and disabling said balance means.

Claim 23

A grain moisture tester oprative to give a direct reading of the moisture content of the grain under test by measuring the dielectric constant of said grain and capable of measuring the moisture content of a plurality of different grains having a plurality of relationships between moisture content and dielectric constant and comprising: a capacitive cell for receiving an amount of the grain to be tested; an oscillator including said cell as a frequency determining element thereof; timer means for generating an electrical signal having a period of predetermined duration; gate means coupled to the output of said timer means and said oscillator for passing the output of said oscillator only during the presence of said timer signal; counter means coupled to the output of said gate means for indicating the number of cycles of said oscillator occurring during said timer signal; means for controlling the duration of said timer siGnal period; recycle means for periodically actuating said timer means; balance means coupled to said counter means and period controlling means and responsive to the indication given on said counter means at the end of said timer period to adjust said timer period to achieve a given indication at the end of each timer period; disabling means for alternately enabling and disabling said balance means; temperature correction means coupled to said timer period controlling means for altering said period by an amount related to the temperature of the grain being tested; nonlinear correction means coupled to said period controlling means for altering said period by an amount related to the frequency of operation of said oscillator; and grain selection means coupled to said period controlling means and comprising slope selection means for altering said period in accord with the slope of a linear approximation to the particular relationship between moisture content ane dielectric constant for the grain under test, intercept selection means for altering said period in accord with the intercept of said linear approximation, and curvature selection means for adjusting the magnitude of the period alteration caused by said nonlinear correction means in accord with the magnitude of the departure of said particular relationship between moisture content and dielectric constant from said linear approximation.

Claim 24

A grain moisture tester oprative to give a direct reading of the moisture content of the grain under test by measuring the dielectric constant of said grain and capable of measuring the moisture content of a plurality of different grains having a plurality of relationships between moisture content and dielectric constant and comprising: a capacitive cell for receiving an amount of the grain to be tested; an oscillator including said cell as a frequency determining element thereof; timer means for generating an electrical signal having a period of predetermined duration; gate means coupled to the output of said timer means and said oscillator for passing the output of said oscillator only during the presence of said timer signal; counter means coupled to the output of said gate means for indicating the number of cycles of said oscillator occurring during said timer signal; means for controlling the duration of said timer siGnal period; recycle means for periodically actuating said timer means; balance means coupled to said counter means and period controlling means and responsive to the indication given on said counter means at the end of said timer period to adjust said timer period to achieve a given indication at the end of each timer period; disabling means for alternately enabling and disabling said balance means; temperature correction means coupled to said timer period controlling means for altering said period by an amount related to the temperature of the grain being tested; nonlinear correction means coupled to said period controlling means for altering said period by an amount related to the frequency of operation of said oscillator; and grain selection means coupled to said period controlling means and comprising slope selection means for altering said period in accord with the slope of a linear approximation to the particular relationship between moisture content ane dielectric constant for the grain under test, intercept selection means for altering said period in accord with the intercept of said linear approximation, and curvature selection means for adjusting the magnitude of the period alteration caused by said nonlinear correction means in accord with the magnitude of the departure of said particular relationship between moisture content and dielectric constant from said linear approximation.

Claim 25

A moisture tester for determining the moisture content of a material under test by measuring an electrical property of said material and including provisions for measuring the moisture content of different materials having a plurality of relationships between moisture content and said measured electrical property comprising: means for producing an alternating electrical signal having a predetermined nominal frequency; means for producing an electrical signal having a predetermined nominal period of duration such that a nominal number of cycles at said predetermined nominal frequency occur during said predetermined nominal period; means for altering said nominal number in accord with the nature of the relationship between moisture content and said measured electrical property for the material under test; means for receiving an amount of the material under test and altering the number of cycles of said alternating electrical signal occurring during said period; and means for counting the number of cycles in said alternating electrical signal occurring during said period and indicating the moisture content of the material under test.

Claim 26

A moisture tester for determining the moisture content of a material under test by measuring an electrical property of said material and including provisions for measuring the moisture content of different materials having a plurality of relationships between moisture content and said measured electrical property comprising: means for producing an alternating electrical signal having a predetermined nominal frequency; means for producing an electrical signal having a predetermined nominal period of duration such that a nominal number of cycles at said predetermined nominal frequency occur during said predetermined nominal period; means for altering said nominal number in accord with the nature of the relationship between moisture content and said measured electrical property for the material under test; means for receiving an amount of the material under test and altering the number of cycles of said alternating electrical signal occurring during said period; and means for counting the number of cycles in said alternating electrical signal occurring during said period and indicating the moisture content of the material under test.

Claim 27

A grain moisture tester for determining the moisture content of a plurality of different types of grain by measuring the dielectric constant of the grain under test and comprising: means for producing an alternating electrical signal having a predetermined nominal frequency; means for producing an electrical signal having a predetermined nominal period of duration such that a nominal number of cycles at said predetermined nominal frequency occur during said predetermined nominal period; means for altering said nominal number in accord with the nature of the particular relationship between moisture content and dielectric constant for the grain under test; means for receiving an amount of the material under test and altering the number of cycles of said alernating electrical signal occurring during said period; and means for counting the number of cycles in said alternating electrical signal occurring during said period and indicating the moisture content of the grain under test.

Claim 28

A grain moisture tester for determining the moisture content of a plurality of different types of grain by measuring the dielectric constant of the grain under test and comprising: means for producing an alternating electrical signal having a predetermined nominal frequency; means for producing an electrical signal having a predetermined nominal period of duration such that a nominal number of cycles at said predetermined nominal frequency occur during said predetermined nominal period; means for altering said nominal number in accord with the nature of the particular relationship between moisture content and dielectric constant for the grain under test; means for receiving an amount of the material under test and altering the number of cycles of said alernating electrical signal occurring during said period; and means for counting the number of cycles in said alternating electrical signal occurring during said period and indicating the moisture content of the grain under test.