US3739629A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Psychrometer and method
Assignee: ELITechGroup Inc
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Filing: 1971-02-09
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Granted: 1973-06-19
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Expires: 1991-02-09
Abstract
Abstract Apparatus and method for use in the measurement of the water or solvent potential of selected samples. The apparatus utilizes a psychrometer principle, which, broadly speaking, relies upon comparison between wet and dry bulb temperatures in a controlled system for obtaining desired measurements. A thermocouple utilized in making psychrometer measurements is concealed within a small psychrometer chamber and is exposed to the sample during testing, being sealed from surrounding environment. The psychrometer chamber is formed by a sample holder and metal heat sink components respectively disposed above and below the sample holder and serve to achieve rapid thermal equilibrium. The interior water potential measuring apparatus including the thermocouple is also thermally insulated to minimize ambient temperature effects. Samples to be analyzed are placed within a cup of a disc-shaped sample holder resting in a slide which can be displaced from side-to-side to position the sample and sample holder medially within the measuring apparatus at the psychrometer chamber. The tightening of a screw insures that the psychrometer chamber is sealed from the surrounding environment, following which vapor pressure equilibration and temperature equilibrium result. A second thermocouple may be provided giving a temperature reading for use in analysis of the electrical output of the psychrometer thermocouple. The output of the psychrometer thermocouple is presented in usable information form at a microvoltmeter which comprises a readout device for the sampling psychrometer.
Inventors
- 👤 E Campbell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:15
CPC Classifications
G; G01; G01N; G01N25/00; G01N25/56; G01N25/62; G01N25/64
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
202 words
A psychrometer comprising: a rigid casing of material having good thermal insulation characteristics; heat sink means disposed within the casing; a transverse slot disposed through the heat sink means; a peltier thermocouple disposed immediately adjacent the transverse slot with the junction of the thermocouple disposed in a chamber which opens directly to the transverse slot; slider means reciprocably situated in the transverse slot for moving samples into alignment with the chamber and for removing samples from the psychrometer; means sealing the sample of external environmental conditions at least when the sample is situated in alignment with the chamber; the heat sink means comprising two parts, one on each side of the transverse slot; the slider means comprises a slide bar by which at least one sample holder is carried; the sample holder and the heat sink means having good thermal conducting properties; the sealing means comprises an ''''O'''' ring interposed between one heat sink part and one surface of the slider means; the sealing means further comprising force-applying means for compressing the two parts of the heat sink means and the sample holder together counter to the memory of the ''''O'''' ring, creating a single thermal mass from the three mentioned components.
Claim 2
Dependent Claim
202 words
A psychrometer comprising: a rigid casing of material having good thermal insulation characteristics; heat sink means disposed within the casing; a transverse slot disposed through the heat sink means; a peltier thermocouple disposed immediately adjacent the transverse slot with the junction of the thermocouple disposed in a chamber which opens directly to the transverse slot; slider means reciprocably situated in the transverse slot for moving samples into alignment with the chamber and for removing samples from the psychrometer; means sealing the sample of external environmental conditions at least when the sample is situated in alignment with the chamber; the heat sink means comprising two parts, one on each side of the transverse slot; the slider means comprises a slide bar by which at least one sample holder is carried; the sample holder and the heat sink means having good thermal conducting properties; the sealing means comprises an ''''O'''' ring interposed between one heat sink part and one surface of the slider means; the sealing means further comprising force-applying means for compressing the two parts of the heat sink means and the sample holder together counter to the memory of the ''''O'''' ring, creating a single thermal mass from the three mentioned components.
Claim 3
Dependent Claim
147 words
A peltier psychrometer for measuring water and solvent potential of a plurality of samples comprising: a casing comprising thermal insulating material; a heat sink mass and peltier thermocouple means situated within the casing; slider means extending through the casing and heat sink mass in slideable relation, the junction of the thermocouple being exposed to part of the slider means within the heat sink mass; means creating and maintaining a sealed relation between the slider means and the heat sink mass to isolate the thermocouple junction and the adjacent portion of the slider means from external environmental conditions; slider means comprising a carrier and spaced sample holders situated in alignment along the carrier, whereby the sample holders may be serially moved from the environment external to the psychrometer to a position adjacent the junction for testing purposes without at any time exposing the junction to external environmental conditions.
Claim 4
Dependent Claim
147 words
A peltier psychrometer for measuring water and solvent potential of a plurality of samples comprising: a casing comprising thermal insulating material; a heat sink mass and peltier thermocouple means situated within the casing; slider means extending through the casing and heat sink mass in slideable relation, the junction of the thermocouple being exposed to part of the slider means within the heat sink mass; means creating and maintaining a sealed relation between the slider means and the heat sink mass to isolate the thermocouple junction and the adjacent portion of the slider means from external environmental conditions; slider means comprising a carrier and spaced sample holders situated in alignment along the carrier, whereby the sample holders may be serially moved from the environment external to the psychrometer to a position adjacent the junction for testing purposes without at any time exposing the junction to external environmental conditions.
Claim 5
Dependent Claim
117 words
A psychrometer comprising: a thermal insulating rigid casing; thermally conductive heat sinks situated within the casing such that a space exists therebetween; the heat sinks being relatively reciprocable within limits one in respect to the other; one heat sink having a moisture-detecting peltier thermocouple associated therewith such that the junction of the thermocouple is exposed at the sapce between the heat sinks; means for introducing a thermally conductive sample holder between the heat sinks so that a sample associated, with the sample holder is positioned directly adjacent the junctioN of the thermocouple; means for forcing the heat sinks into firm contiguous relation with the sample holder thereby creating a single thermal mass to insure rapid thermal equilibrium.
Claim 6
Dependent Claim
117 words
A psychrometer comprising: a thermal insulating rigid casing; thermally conductive heat sinks situated within the casing such that a space exists therebetween; the heat sinks being relatively reciprocable within limits one in respect to the other; one heat sink having a moisture-detecting peltier thermocouple associated therewith such that the junction of the thermocouple is exposed at the sapce between the heat sinks; means for introducing a thermally conductive sample holder between the heat sinks so that a sample associated, with the sample holder is positioned directly adjacent the junctioN of the thermocouple; means for forcing the heat sinks into firm contiguous relation with the sample holder thereby creating a single thermal mass to insure rapid thermal equilibrium.
Claim 7
Dependent Claim
28 words
A psychrometer as defined in claim 3 further comprising an anular seal interposed between one heat sink and the introduced sample holder to create a sealed relation therebetween.
Claim 8
Dependent Claim
23 words
A psychrometer as defined in claim 3 wherein the thermocouple junction is disposed within a small cavity existing at the one heat sink.
Claim 9
Dependent Claim
180 words
A peltier psychrometer assembly comprising: a casing having thermal insulating properties serially comprising a first end portion, an intermediate portion and a second end portion, secured together in aligned and contiguous relation by fastener means; one thermally conductive heat sink being rigidly held in an internal blind bore of one end portion of the casing; an opening disposed at the interface between the one end portion and the intermediate portion of the casing, the one heat sink being exposed at the opening; means displaceably situated in the opening for introducing thermally conductive sample-confining holders within the casing at the interface; a second heat sink being reciprocably carried within a central bore of the intermediate portion of the casing in exposed relation to the opening; a peltier thermocouple held centrally within the second heat sink, the junction of the thermocouple being exposed adjacent the opening; force-applying means centrally carried by the other end portion of the casing urging the second heat sink toward the opening, causing the heat sinks to respectively be contiguous with a sample-confining holder disposed at the interface.
Claim 10
Dependent Claim
180 words
A peltier psychrometer assembly comprising: a casing having thermal insulating properties serially comprising a first end portion, an intermediate portion and a second end portion, secured together in aligned and contiguous relation by fastener means; one thermally conductive heat sink being rigidly held in an internal blind bore of one end portion of the casing; an opening disposed at the interface between the one end portion and the intermediate portion of the casing, the one heat sink being exposed at the opening; means displaceably situated in the opening for introducing thermally conductive sample-confining holders within the casing at the interface; a second heat sink being reciprocably carried within a central bore of the intermediate portion of the casing in exposed relation to the opening; a peltier thermocouple held centrally within the second heat sink, the junction of the thermocouple being exposed adjacent the opening; force-applying means centrally carried by the other end portion of the casing urging the second heat sink toward the opening, causing the heat sinks to respectively be contiguous with a sample-confining holder disposed at the interface.
Claim 11
Dependent Claim
26 words
A psychrometer as defined in claim 6 further comprising an annular seal interposed between the second heat sink and the sample-confining holder disposed at the interface.
Claim 12
Dependent Claim
168 words
In a method of measuring water and solvent potential of samples, the steps of: transversely introducing one sample disposed within one sample carrier carried by a slide mechanism from outside a peltier psychrometer into a sample chamber of the psychrometer by displacement of the slide mechanism while maintaining the sample chamber and slide mechanism at the sample chamber sealed from the environment outside the psychrometer, the junction of the thermocouple of the psychrometer being exposed within the sample chamber; testing the sample by use of the thermocouple to obtain a measure of the water or solvent potential of the sample; and transversely introducing a second sample disposed in a second sample carrier carried by the slide mechanism from outside the psychrometer into the sample chamber and simultaneously removing the one sample and the one sample carrier from the sample chamber to a position outside the psychrometer by displacement of the slide mechanism while maintaining the sample chamber and slide mechanism at the sample chamber in said sealed condition.
Claim 13
Dependent Claim
168 words
In a method of measuring water and solvent potential of samples, the steps of: transversely introducing one sample disposed within one sample carrier carried by a slide mechanism from outside a peltier psychrometer into a sample chamber of the psychrometer by displacement of the slide mechanism while maintaining the sample chamber and slide mechanism at the sample chamber sealed from the environment outside the psychrometer, the junction of the thermocouple of the psychrometer being exposed within the sample chamber; testing the sample by use of the thermocouple to obtain a measure of the water or solvent potential of the sample; and transversely introducing a second sample disposed in a second sample carrier carried by the slide mechanism from outside the psychrometer into the sample chamber and simultaneously removing the one sample and the one sample carrier from the sample chamber to a position outside the psychrometer by displacement of the slide mechanism while maintaining the sample chamber and slide mechanism at the sample chamber in said sealed condition.
Claim 14
Dependent Claim
208 words
In a method of measuring water and solvent potential of a sample, the steps of: placing a sample holder with the sample within a test chamber of a psychrometer where the junction of a peltier thermocouple is exposed to the sample by moving carrier means which hold a plurality of spaced samples in respect to the thermocouple; creating and maintaining a seal against the carrier means between the test chamber and the external environment enabling successive delivery of samples to the test chamber by periodic displacement of the carrier means without exposing the junction to external environmental conditions; isolating the sample within the test chamber; allowing thermal equilibrium and water or solvent pressure equilibration to occur within the test chamber; measuring the dry bulb electromotive force at the junction of the peltier thermocouple; subjecting the junction of the thermocouple to peltier cooling, causing condensation of water or solvent at the junction; terminating The peltier cooling; measuring the wet bulb electromotive force at the junction once constancy is reached; determining the difference between the dry and wet bulb electromotive forces at the junction in the isolated gaseous atmosphere of the test chamber as a measure of the relative partial pressure of the gas form of the water or solvent.
Claim 15
Dependent Claim
208 words
In a method of measuring water and solvent potential of a sample, the steps of: placing a sample holder with the sample within a test chamber of a psychrometer where the junction of a peltier thermocouple is exposed to the sample by moving carrier means which hold a plurality of spaced samples in respect to the thermocouple; creating and maintaining a seal against the carrier means between the test chamber and the external environment enabling successive delivery of samples to the test chamber by periodic displacement of the carrier means without exposing the junction to external environmental conditions; isolating the sample within the test chamber; allowing thermal equilibrium and water or solvent pressure equilibration to occur within the test chamber; measuring the dry bulb electromotive force at the junction of the peltier thermocouple; subjecting the junction of the thermocouple to peltier cooling, causing condensation of water or solvent at the junction; terminating The peltier cooling; measuring the wet bulb electromotive force at the junction once constancy is reached; determining the difference between the dry and wet bulb electromotive forces at the junction in the isolated gaseous atmosphere of the test chamber as a measure of the relative partial pressure of the gas form of the water or solvent.
References Cited (Backward Citations)
US2676417A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-18 | 1976-12-18 | 1977-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-18 | 1980-12-18 | 1981-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-18 | 1984-12-18 | 1985-06-19 | $7700.00 | Window Closed / Lapsed |