US3789296A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moisture monitor system
Assignee: Individual
•
Filing: 1972-06-12
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Granted: 1974-01-29
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Expires: 1992-06-12
Abstract
Abstract A time domain reflectometer type of electronic instrument is provided which uses pulse reflectometry techniques for precisely monitoring the water content of a monitored product. The instrument may be used, for example, to monitor the quantity of liquid latex applied as an adhesive backing coating during the manufacture of carpeting. In such a case, the instrument assures a uniform backing of sufficient latex on the carpet to perform its intended function, but without wastage. The instrument, however, has other uses, such as for monitoring the water content in the production of paper, or in textile dying processes, or the like. In the practice of the invention, the product being monitored is passed as a continuous sheet through a pair of sensor bars, and the system of the invention measures the effective dielectric constant produced by the product as it passes between the bars. The sensor bars serve as a two-wire transmission line, and the system transmits narrow electric pulses down the transmission line and receives reflected pulses therefrom. The system uses radar principles, however, the signal is completely contained between the two sensor bars and the pulse returns are continuously received from successive points across the product. The size of the return is related to the amount of moisture content at each point along the product.
Inventors
- 👤 J Scarbrough
- 👤 P Caruso
- 👤 L Rasmussen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:17
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/22; G01N27/223; G01R; G01R27/00; G01R27/02; G01R27/26; G01R27/2617; G01R27/2623
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
104 words
Apparatus for sensing the amount of dielectric coating applied to a web-like carrier, said apparatus comprising: a pair of spaced electrically conductive elongated sensor bars which serve as a two-wire transmission line between which the web-like carrier and its dielectric coating are drawn, and which extend transversely of the web-like carrier; and a time domain reflectometer circuit electrically connected to said sensor bars to transmit electric pulses down the transmission line and to receive pulses reflected from the dielectric coating so as to measure changes in the amount of moisture in said dielectric coating as the web-like carrier is drawn between said sensor bars.
Claim 2
Dependent Claim
104 words
Apparatus for sensing the amount of dielectric coating applied to a web-like carrier, said apparatus comprising: a pair of spaced electrically conductive elongated sensor bars which serve as a two-wire transmission line between which the web-like carrier and its dielectric coating are drawn, and which extend transversely of the web-like carrier; and a time domain reflectometer circuit electrically connected to said sensor bars to transmit electric pulses down the transmission line and to receive pulses reflected from the dielectric coating so as to measure changes in the amount of moisture in said dielectric coating as the web-like carrier is drawn between said sensor bars.
Claim 3
Dependent Claim
41 words
The apparatus defined in claim 1, in which said time domain reflectometer circuit includes an oscilloscope display means and an electric pulse generating circuit, and which includes an electrically conductive coaxial cable connecting said pulse generating circuit to said sensor bars.
Claim 4
Dependent Claim
26 words
The apparatus defined in claim 2, and which includes a transition connector connecting said coaxial cable to the two-wire transmission line formed by said sensor bars.
Claim 5
Dependent Claim
124 words
Apparatus for sensing the amount of dielectric coating applied to a web-like carrier, said apparatus comprising: a pair of spaced electrically conductive elongated sensor elements which serve as a two-wire transmission line between which the web-like carrier and its dielectric coating are drawn, and which extend transversely of the web-like carrier; a time domain reflectometer circuit electrically connected to said sensor elements to transmit electric pulses down the transmission line and to receive pulses reflected from the dielectric coating so as to measure changes in the amount of moisture in said dielectric coating as the web-like carrier is drAwn between said sensor bars; and signal condition electronic circuitry coupled to said time domain reflectometer circuit to eliminate the effects of drift in the system.
Claim 6
Dependent Claim
124 words
Apparatus for sensing the amount of dielectric coating applied to a web-like carrier, said apparatus comprising: a pair of spaced electrically conductive elongated sensor elements which serve as a two-wire transmission line between which the web-like carrier and its dielectric coating are drawn, and which extend transversely of the web-like carrier; a time domain reflectometer circuit electrically connected to said sensor elements to transmit electric pulses down the transmission line and to receive pulses reflected from the dielectric coating so as to measure changes in the amount of moisture in said dielectric coating as the web-like carrier is drAwn between said sensor bars; and signal condition electronic circuitry coupled to said time domain reflectometer circuit to eliminate the effects of drift in the system.
Claim 7
Dependent Claim
62 words
The apparatus defined in claim 4, in which said signals conditioning electronic circuitry includes means for sampling two reflected signals from said reflectometer circuit, means for inverting one of the sampled signals, and integrator means for summing the sampled signals to produce a direct current output signal having an amplitude directly proportional to the average difference of impedance in the sampled areas.
Claim 8
Dependent Claim
25 words
The apparatus defined in claim 3, and which includes a recorder connected to said signal conditioning electronic circuitry for recording said direct current output signal.
Claim 9
Dependent Claim
52 words
The apparatus defined in claim 5, and which includes an impedance step element interposed in said coaxial cable, and in which said sampling means in said electronic circuitry samples a reference signal corresponding to a portion of the length of said coaxial cable connecting said impedance step element to said sensor elements.
Claim 10
Dependent Claim
29 words
The apparatus defined in claim 7, in which said sampling means of said electronic circuitry samples the second signal to correspond to a transverse portion of said web-like carrier.
Claim 11
Dependent Claim
22 words
The apparatus defined in claim 1, in which said dielectric coating applied to said web-like carrier comprises latex applied to a carpet.
Claim 12
Dependent Claim
49 words
The apparatus defined in claim 2, in which one of said bars constitutes a signal bar and the other of said bars constitutes a ground bar, and which includes a transition cone mounted at one end of said signal bar to connect said signal bar to said coaxial cable.
Claim 13
Dependent Claim
199 words
Apparatus for sensing the amount of dielectric coating applied to a web-like carrier, said apparatus comprising: a pair of spaced electrically conductive elongated sensor elements which serve as a two-wire transmission line between which the web-like carrier and its dielectric coating are drawn, and which extend transversely of the web-like carrier; a time domain reflectometer circuit electrically connected to said sensor elements to transmit electric pulses down the transmission line and to receive pulses reflected from the dielectric coating so as to measure changes in the amount of moisture in said dielectric coating as the web-like carrier is drawn between said sensor elements; and which includes signal conditioning electronic circuitry coupled to said time domain reflectometer circuit to eliminate the effects of drift in the system, said signal conditioning circuitry including a plurality of sampling means, each sampling two reflected signals corresponding to different side-by-side segments of the dielectric coating on the web-like carrier; and each of said sampling means including means for inverting one of the sampled signals, and integrator means for summing the sampled signals to produce a direct current output signal having an amplitude directly proportional to the average difference of impedance in the sampled segments.
Claim 14
Dependent Claim
199 words
Apparatus for sensing the amount of dielectric coating applied to a web-like carrier, said apparatus comprising: a pair of spaced electrically conductive elongated sensor elements which serve as a two-wire transmission line between which the web-like carrier and its dielectric coating are drawn, and which extend transversely of the web-like carrier; a time domain reflectometer circuit electrically connected to said sensor elements to transmit electric pulses down the transmission line and to receive pulses reflected from the dielectric coating so as to measure changes in the amount of moisture in said dielectric coating as the web-like carrier is drawn between said sensor elements; and which includes signal conditioning electronic circuitry coupled to said time domain reflectometer circuit to eliminate the effects of drift in the system, said signal conditioning circuitry including a plurality of sampling means, each sampling two reflected signals corresponding to different side-by-side segments of the dielectric coating on the web-like carrier; and each of said sampling means including means for inverting one of the sampled signals, and integrator means for summing the sampled signals to produce a direct current output signal having an amplitude directly proportional to the average difference of impedance in the sampled segments.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |