US3776024A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Densitometer components
Assignee: TDK Micronas GmbH
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Filing: 1971-07-09
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Granted: 1973-12-04
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Expires: 1991-07-09
Abstract
Abstract A vibration densitometer including a vane adapted to be vibrated, a driver coil located around a magnetostrictive body to vibrate the vane, and a piezoelectric crystal to detect the vane vibrations. A loop connects the crystal to the coil, the loop having a tracking filter to pass tbe resonant frequency of the crystal output. A linearization circuit is connected from the filter output to produce an analog voltage directly proportional to the density of the fluid in which the vane is located. A switch is actuable to clamp the circuit output to a constant magnitude to indicate the lack of resonance. The switch is actuated by a synchronous detector connected from the input and output of the tracking filter. An alternating signal is transformer coupled to an input circuit with rectification to provide an isolated source of potential without the use of a power supply.
Inventors
- 👤 G Schlatter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:25
CPC Classifications
G; G01; G01N; G01N9/00; G01N9/002; G01N2009/008
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
343 words
A vibration densitometer comprising: a probe; a structure mounted on said probe in a manner to be vibrated while immersed in a fluid; first means mounted on said probe to vibrate said structure; an electrical pick-off mounted on said probe in a position to produce at its output, alternating signals at least at some of the frequencies at which said structure vibrates; a regenerative loop connected from said pick-off output to said first means to vibrate said structure at its resonant frequency, said loop including a tracking filter having an input and an output, a driver amplifier connected from said tracking filter output to said first means, and second means connected from said pick-off output to said tracking filter input for impressing a periodic wave on said tracking filter, said periodic wave having an A.C. component of a frequency directly proportional to the frequency at which said structure vibrates; control means having first and second inputs and an output; output means connected from said tracking filter output to said control means first input for impressing a first signal on said control means first input which is proportional to the density of the said fluid surrounding said structure, said control means being actuable in response to a second sign impressed upon said second input thereof to produce a third signal at the output thereof, said third signal having a constant magnitude, said control means being deactuable in response to a fourth signal impressed upon said second input thereof to produce a fifth signal at the output thereof, said fifth signal being directly proportional to said first signal; third means connected from the input and the output of said tracking filter to said control means second input, said third means impRessing said second signal on said control means second input when the tracking filter input and output signals have different frequencies, said third means impressing said fourth signal on said control means second input when the tracking filter input and output signals have the same frequency; and utilization means connected from said control means output.
Claim 2
Dependent Claim
343 words
A vibration densitometer comprising: a probe; a structure mounted on said probe in a manner to be vibrated while immersed in a fluid; first means mounted on said probe to vibrate said structure; an electrical pick-off mounted on said probe in a position to produce at its output, alternating signals at least at some of the frequencies at which said structure vibrates; a regenerative loop connected from said pick-off output to said first means to vibrate said structure at its resonant frequency, said loop including a tracking filter having an input and an output, a driver amplifier connected from said tracking filter output to said first means, and second means connected from said pick-off output to said tracking filter input for impressing a periodic wave on said tracking filter, said periodic wave having an A.C. component of a frequency directly proportional to the frequency at which said structure vibrates; control means having first and second inputs and an output; output means connected from said tracking filter output to said control means first input for impressing a first signal on said control means first input which is proportional to the density of the said fluid surrounding said structure, said control means being actuable in response to a second sign impressed upon said second input thereof to produce a third signal at the output thereof, said third signal having a constant magnitude, said control means being deactuable in response to a fourth signal impressed upon said second input thereof to produce a fifth signal at the output thereof, said fifth signal being directly proportional to said first signal; third means connected from the input and the output of said tracking filter to said control means second input, said third means impRessing said second signal on said control means second input when the tracking filter input and output signals have different frequencies, said third means impressing said fourth signal on said control means second input when the tracking filter input and output signals have the same frequency; and utilization means connected from said control means output.
Claim 3
Dependent Claim
15 words
The invention as defined in claim 1, wherein said third means includes a synchronous detector.
Claim 4
Dependent Claim
42 words
The invention as defined in claim 2, wherein said second means includes a first amplifier and a first squarer connected in succession from said pick-off to said tracking filter input, said synchronous detector being connected from the output of said first amplifier.
Claim 5
Dependent Claim
77 words
The invention as defined in claim 3, including a second amplifier and a second squarer connected from the tracking filter output, said driver amplifier being connected from the output of said second amplifier, a filter frequency control circuit connected to said tracking filter, and a phase detector connected from the outputs of said squarers to said control circuit, and a differentiator connected from the output of said second squarer to said synchronous detector and said output means.
Claim 6
Dependent Claim
331 words
A vibration densitometer comprising: a probe; a structure mounted on said probe in a manner to be vibrated while immersed in a fluid; first means mounted on said probe to vibrate said structure; an electrical pick-off mounted on said probe in a position to produce at its output, alternating signals at least at some of the frequencies at which said structure vibrates; a regenerative loop connected from said pick-off output to said first means to vibrate said structure at its resonant frequency, said loop including a tracking filter having an input and an output, a driver amplifier connected from said tracking filter output to said first means, and second means connected from said pick-off output to said tracking filter input for impressing an alternating signal on said tracking filter of a frequency equal to said resonant frequency; control means having first and second inputs and an output; output means connected from said tracking filter output to said control means first input for impressing a first signal on said control means first input which is proportional to the density of the said fluid surrounding said structure, said control means being actuable in response to a second signal impressed upon said second input thereof to produce a third signal at the output thereof, said third signal having a constant magnitude, said control means being deactuable in response to a fourth signal impressed upon said second input thereof to produce a fifth signal at the output thereof, said fifth signal being directly proportional to said first signal; third means connected from the input and the output of said tracking filter to said control means second input, said third means impressing said second signal on said control means second input when the tracking filter input and output signals have different frequencies, said third means impressing said fourth signal on said control means second input when the tracking filter input and output signals have the same frequency; and utilization means connected from said control means output.
Claim 7
Dependent Claim
331 words
A vibration densitometer comprising: a probe; a structure mounted on said probe in a manner to be vibrated while immersed in a fluid; first means mounted on said probe to vibrate said structure; an electrical pick-off mounted on said probe in a position to produce at its output, alternating signals at least at some of the frequencies at which said structure vibrates; a regenerative loop connected from said pick-off output to said first means to vibrate said structure at its resonant frequency, said loop including a tracking filter having an input and an output, a driver amplifier connected from said tracking filter output to said first means, and second means connected from said pick-off output to said tracking filter input for impressing an alternating signal on said tracking filter of a frequency equal to said resonant frequency; control means having first and second inputs and an output; output means connected from said tracking filter output to said control means first input for impressing a first signal on said control means first input which is proportional to the density of the said fluid surrounding said structure, said control means being actuable in response to a second signal impressed upon said second input thereof to produce a third signal at the output thereof, said third signal having a constant magnitude, said control means being deactuable in response to a fourth signal impressed upon said second input thereof to produce a fifth signal at the output thereof, said fifth signal being directly proportional to said first signal; third means connected from the input and the output of said tracking filter to said control means second input, said third means impressing said second signal on said control means second input when the tracking filter input and output signals have different frequencies, said third means impressing said fourth signal on said control means second input when the tracking filter input and output signals have the same frequency; and utilization means connected from said control means output.
Claim 8
Dependent Claim
15 words
The invention as defined in claim 5, wherein said third means includes a synchronous detector.
Claim 9
Dependent Claim
42 words
The invention as defined in claim 6, wherein said second means includes a first amplifier and a first squarer connected in succession from said pick-off to said tracking filter input, said synchronous detector being connected from the output of said first amplifier.
Claim 10
Dependent Claim
77 words
The invention as defined in claim 7, including a second amplifier and a second squarer connected from the tracking filter output, said driver amplifier being connected from the output of said second amplifier, a filter frequency control circuit connected to said tracking filter, and a phase detector connected from the outputs of said squarers to said control circuit, and a differentiator connected from the output of said second squarer to said synchronous detector and said output means.
Claim 11
Dependent Claim
299 words
A vibration densitometer comprising: a probe; a structure mounted on said probe in a manner to be vibrated while immersed in a fluid; first means mounted on said probe to vibrate said structure; an electrical pick-off mounted on said probe in a position to produce, at its output, alternating signals at least at some of the frequencies at which said structure vibrates; a regenerative loop including an input circuit, a first amplifier, a first squarer, a tracking filter, a second amplifier and a driver amplifier connected as successive stages in that order from the output of said pick-off to the input of said first means, said input circuit including preamplifier means for impressing an alternating signal on said first amplifier of an amplitude greater than that of the output signal of said pick-off but of the same frequency as the output signal of said pick-off; a synchronous detector having an output and first and second inputs; a linearization circuit having an input and an output; a differentiator; a second squarer connected from the output of said second amplifier to said differentiator, said differentiator having its input connected from said second squarer and its first and second outputs connected respectively to said synchronous detector first input and to said linearization circuit input; and control means having first and second inputs and an output, said control means first input being connected from said linearization circuit output; and utilization means connected from said control means output, said control means second input being connected from said synchronous detector output, said synchronous detector second input being connected from the output of said first amplifier said linearization circuit including means for impressing a signal on said control means first input directly proportional to the density of the said fluid in which said structure is immersed.
Claim 12
Dependent Claim
299 words
A vibration densitometer comprising: a probe; a structure mounted on said probe in a manner to be vibrated while immersed in a fluid; first means mounted on said probe to vibrate said structure; an electrical pick-off mounted on said probe in a position to produce, at its output, alternating signals at least at some of the frequencies at which said structure vibrates; a regenerative loop including an input circuit, a first amplifier, a first squarer, a tracking filter, a second amplifier and a driver amplifier connected as successive stages in that order from the output of said pick-off to the input of said first means, said input circuit including preamplifier means for impressing an alternating signal on said first amplifier of an amplitude greater than that of the output signal of said pick-off but of the same frequency as the output signal of said pick-off; a synchronous detector having an output and first and second inputs; a linearization circuit having an input and an output; a differentiator; a second squarer connected from the output of said second amplifier to said differentiator, said differentiator having its input connected from said second squarer and its first and second outputs connected respectively to said synchronous detector first input and to said linearization circuit input; and control means having first and second inputs and an output, said control means first input being connected from said linearization circuit output; and utilization means connected from said control means output, said control means second input being connected from said synchronous detector output, said synchronous detector second input being connected from the output of said first amplifier said linearization circuit including means for impressing a signal on said control means first input directly proportional to the density of the said fluid in which said structure is immersed.
Claim 13
Dependent Claim
33 words
The invention as defined in claim 9, including a filter frequency control circuit connected to said tracking filter, and a phase detector connected from the outputs of said squarers to said control circuit.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-03 | 1977-06-04 | 1977-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-03 | 1981-06-04 | 1981-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-03 | 1985-06-04 | 1985-12-04 | $7700.00 | Window Closed / Lapsed |