US4364676A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat transfer meter
Assignee: Memoteknik AB
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Filing: 1980-03-13
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Granted: 1982-12-21
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Expires: 2000-03-13
Abstract
Abstract PCT No. PCT/SE80/00077 Sec. 371 Date Nov. 13, 1980 Sec. 102(e) Date Nov. 13, 1980 PCT Filed Mar. 13, 1980 PCT Pub. No. WO80/01954 PCT Pub. Date Sep. 18, 1980.The invention relates to a portable, battery-driven device for measuring heat transfer coefficients (k-values). It uses an amplifier (1), which forms the quotient between the inner temperature minus the inner wall temperature on one hand and the inner temperature minus the outer temperature on the other hand. The temperature values of the first-mentioned substraction are obtained by thermal elements (7, 8), which are connected to the device. The difference according to the second one of the substractions is adjustable connected in a feed back circuit of the amplifier (1). The output quantity of the latter is supplied to an instrument (3) graduated in k-value. The thermal element for the measuring of the inner wall temperature can be provided at the tip of a probe (9), and may consequently be conveniently applied to different places of a wall to be investigated.
Inventors
- 👤 Viktor Oja
- 👤 Sigvard Wikstrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:49
CPC Classifications
G; G01; G01N; G01N25/00; G01N25/18
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
202 words
A device for measuring a heat transmission coefficient for a wall portion separating an inner media having a temperature t i and an outer media having a temperature t u , comprising: an amplifier having an input and an output; an indicator coupled to said output for indicating the measured heat transfer coefficient; first thermal sensor means adapted for sensing a temperature t v of said wall portion at a surface thereof on its inner media side; second thermal sensor means for sensing said temperature t i of said inner media, said first and second thermal sensors being connected by an input circuit coupled to said amplifier input to provide a signal proportional to (t i -t v ); and feedback circuit means coupled at least in part from said output to said input, said circuit being adjustable to provide a feedback signal to said input for causing the gain of said amplifier to be proportional to 1/(t i -t u ), whereby there is developed at said output a signal proportional to A(t i -t v )/(t i -t u ) indicative of said heat transmission coefficient, where A is a constant selected for calibrating said indicator to a predetermined scale.
Claim 2
Independent Claim
202 words
A device for measuring a heat transmission coefficient for a wall portion separating an inner media having a temperature t i and an outer media having a temperature t u , comprising: an amplifier having an input and an output; an indicator coupled to said output for indicating the measured heat transfer coefficient; first thermal sensor means adapted for sensing a temperature t v of said wall portion at a surface thereof on its inner media side; second thermal sensor means for sensing said temperature t i of said inner media, said first and second thermal sensors being connected by an input circuit coupled to said amplifier input to provide a signal proportional to (t i -t v ); and feedback circuit means coupled at least in part from said output to said input, said circuit being adjustable to provide a feedback signal to said input for causing the gain of said amplifier to be proportional to 1/(t i -t u ), whereby there is developed at said output a signal proportional to A(t i -t v )/(t i -t u ) indicative of said heat transmission coefficient, where A is a constant selected for calibrating said indicator to a predetermined scale.
Claim 3
Dependent Claim
50 words
A device according to claim 1 further including a housing in which is mounted said amplifier, indicator, second thermal sensor and feedback circuit; and a probe, coupled to said housing, for containing said first thermal sensor so positioned that it can be brought into contact with said wall portion surface.
Claim 4
Dependent Claim
35 words
A device according to claim 1 or 2 wherein said feedback circuit comprises a manually adjustable potentiometer having positional settings corresponding to the temperature difference between inner and outer media (t i -t u ).
Claim 5
Dependent Claim
23 words
A device according to claim 1 or 2 wherein said input circuit comprises a series connection of said first and second thermal sensors.
Claim 6
Dependent Claim
21 words
A device according to claim 3 wherein said input circuit comprises a series connection of said first and second thermal sensors.
Claim 7
Dependent Claim
15 words
A device according to claim 1 or 2 wherein said amplifier is an operational amplifier.
Claim 8
Dependent Claim
13 words
A device according to claim 3 wherein said amplifier is an operational amplifier.
Claim 9
Dependent Claim
13 words
A device according to claim 4 wherein said amplifier is an operational amplifier.
Claim 10
Dependent Claim
13 words
A device according to claim 5 wherein said amplifier is an operational amplifier.
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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) | 1985-12-20 | 1986-06-21 | 1986-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-20 | 1990-06-21 | 1990-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-20 | 1994-06-21 | 1994-12-21 | $7700.00 | Window Closed / Lapsed |