US3840305A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electro-optical apparatus with temperature compensation
Assignee: TDK Micronas GmbH
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Filing: 1973-07-20
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Granted: 1974-10-08
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Expires: 1993-07-20
Abstract
Abstract A photometric analyzer for stack gases such as SO2 and/or NO2 wherein a gas temperature sensor is connected in the negative feedback path of a differential amplifier. The amplifier circuit removes temperature error from the analyzer output. A nickel resistor, when employed for the sensor, has been found to possess exceptionally good utility in helping to provide good temperature compensation. Switchover to a constant resistance feedback path gives a better curve fit below a temperature of, for example, about 345* K.
Inventors
- 👤 D Sacarisen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:31
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/27; H; H03; H03G; H03G1/00; H03G1/0005; H03G1/0035; H03G1/0041
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
182 words
Electro-optical apparatus comprising: a photometric analyzer having a probe mountable in a position such that an inner end thereof can extend inside at least partial enclosure means containing one or more materials, said probe inner end being positionable spaced inwardly in from the internal surface of the enclosure means wall, said photometric analyzer having an output end and being constructed to produce an output signal So thereon, where So eoet, eo being a signal directly proportional to a parameter of one of said materials, et being a dimensionless function of the temperature t in degrees Kelvin of said one material; variable gain means having an input lead connected from said photometric analyzer output lead, and an output lead; and a first temperature sensor adapted to be mounted in proximity to said one material, said first temperature sensor being connected to said variable gain means in a manner to cause said variable gain means to produce an output signal on said output lead thereof which is directly proportional to the product of the photometric analyzer output signal So and the reciprocal of et.
Claim 2
Dependent Claim
182 words
Electro-optical apparatus comprising: a photometric analyzer having a probe mountable in a position such that an inner end thereof can extend inside at least partial enclosure means containing one or more materials, said probe inner end being positionable spaced inwardly in from the internal surface of the enclosure means wall, said photometric analyzer having an output end and being constructed to produce an output signal So thereon, where So eoet, eo being a signal directly proportional to a parameter of one of said materials, et being a dimensionless function of the temperature t in degrees Kelvin of said one material; variable gain means having an input lead connected from said photometric analyzer output lead, and an output lead; and a first temperature sensor adapted to be mounted in proximity to said one material, said first temperature sensor being connected to said variable gain means in a manner to cause said variable gain means to produce an output signal on said output lead thereof which is directly proportional to the product of the photometric analyzer output signal So and the reciprocal of et.
Claim 3
Dependent Claim
22 words
The invention as defined in claim 1, including utilization Means having an input lead connected from said variable gain means output lead.
Claim 4
Dependent Claim
36 words
The invention as defined in claim 2, wherein said variable gain means output signal is a voltage, said utilization means including a voltmeter calibrated in volume per unit volume, each of said materials being a gas.
Claim 5
Dependent Claim
35 words
The invention as defined in claim 3, wherein et is defined by et -At + B where, A is a positive constant per degree Kelvin but otherwise dimensionless, and B is a positive dimensionless constant.
Claim 6
Dependent Claim
108 words
The invention as defined in claim 4, wherein said variable gain means includes an input junction, an amplifier having an inverting input lead connected from said input junction, and an output lead, first means providing resistance connected from said variable gain means input lead to said input junction, said first temperature sensor including a temperature sensitive first resistor having first and second leads, second means connecting said input junction to said first lead of said first resistor, first branch means for connecting said second lead of said first resistor to said amplifier output lead, and means connecting said amplifier output lead to said variable gain means output lead.
Claim 7
Dependent Claim
53 words
The invention as defined in claim 5, wherein said amplifier is a differential amplifier, said amplifier having a non-inverting input lead, and source means connected from said amplifier non-inverting input lead to maintain the same at a constant D.C. potential, said source means being adjustable to change the amplitude of said D.C. potential.
Claim 8
Dependent Claim
135 words
The invention as defined in claim 6, wherein a second temperature sensor is also provided which is adapted to be mounted in proximity to said one material, said first branch means including a single-pole, double-throw switch having a pole and first and second contacts, means connecting said second lead of said first resistor to said first contact, means connecting said pole to said amplifier output lead, means providing temperature insensitive resistance connected from said input junction to said second contact, and means connected from said second temperature sensor for moving said pole into engagement with said second contact when the temperature of said second temperature sensor is below a predetermined temperature and for moving said pole into engagement with said first contact when the temperature of said second temperature sensor is above said predetermined temperature.
Claim 9
Dependent Claim
14 words
The invention as defined in claim 7, wherein said predetermined temperature is about 345*.
Claim 10
Dependent Claim
117 words
The invention as defined in claim 8, wherein said first resistor has a first resistance which is a function of temperature in degrees Kelvin, said first resistance being approximately equal to R(t) where, R(t) Rof(t), and Ro is the resistance of said first resistor at a temperature t to, said first means having an equivalent series resistance equal to Ra, the sum of the equivalent series resistances of said first branch means and said second means being equal to Rb, said first resistor, said first branch means, and said first and second means being constructed in a manner such that f(t) ((C/-At + B))((Ra/Ro)) - ((Rb/Ro)) where C is an arbitrary positive dimensionless constant larger than zero.
Claim 11
Dependent Claim
15 words
The invention as defined in claim 9, wherein said first resistor is made of nickel.
Claim 12
Dependent Claim
35 words
The invention as defined in claim 1, wherein et is defined by et -At + B where, A is a positive constant per degree Kelvin but otherwise dimensionless, and B is a positive dimensionless constant.
Claim 13
Dependent Claim
35 words
The invention as defined in claim 2, wherein et is defined by et -At + B where, A is a positive constant per degree Kelvin but otherwise dimensionless, and B is a positive dimensionless constant.
Claim 14
Dependent Claim
108 words
The invention as defined in claim 2, wherein said variable gain means includes an input junction, an amplifier having an inverting input lead connected from said input junction, and an output lead, first means providing resistance connected from said variable gain means input lead to said input junction, said first temperature sensor including a temperature sensitive first resistor having first and second leads, second means connecting said input junction to said first lead of said first resistor, first branch means for connecting said second lead of said first resistor to said amplifier output lead, and means connecting said amplifier output lead to said variable gain means output lead.
Claim 15
Dependent Claim
135 words
The invention as defined in claim 13, wherein a second temperature sensor is also provided which is adapted to be mounted in proximity to said one material, said first branch means including a single-pole, double-throw switch having a pole and first and second contacts, means connecting said second lead of said first resistor to said first contact, means connecting said pole to said amplifier output lead, means providing temperature insensitive resistance connected from said input junction to said second contact, and means connected from said second temperature sensor for moving said pole into engagement with said second contact when the temperature of said second temperature sensor is below a predetermined temperature and for moving said pole into engagement with said first contact when the temperature of said second temperature sensor is above said predetermined temperature.
Claim 16
Dependent Claim
15 words
The invention as defined in claim 14, wherein said first resistor is made of nickel.
Claim 17
Dependent Claim
144 words
The invention as defined in claim 14, wherein said first resistor has a first resistance which is a function of temperature in degrees Kelvin, said first resistance being approximately equal to R(t) where, R(t) Rof(t), and Ro is the resistance of said first resistor at a temperature t to, said first means having an equivalent series resistance equal to Ra, the sum of the equivalent series resistances of said first branch means and said second means being equal to Rb, said first resistor, said first branch means, and said first and second means being constructed in a manner such that f(t) ((C/-At + B))((Ra/Ro)) - ((Rb/Ro)) where C is an arbitrary positive dimensionless constant larger than zero, et being defined by et -At + B where, A is a positive constant per degree Kelvin but otherwise dimensionless, and B is a positive dimensionless constant.
Claim 18
Dependent Claim
15 words
The invention as defined in claim 16, wherein said first resistor is made of nickel.
Claim 19
Dependent Claim
15 words
The invention as defined in claim 13, wherein said first resistor is made of nickel.
Claim 20
Dependent Claim
144 words
The invention as defined in claim 13, wherein said first resistor has a first resistance which is a function of temperature in degrees Kelvin, said first resistance being approximately equal to R(t) where, R(t) Rof(t), and Ro is the resistance of said first resistor at a temperature t to, said first means having an equivalent series resistance equal to Ra, the sum of the equivalent series resistances of said first branch means and said second means being equal to Rb, said first resistor, said first branch means, and said first and second means being constructed in a manner such that f(t) ((C/-At + B))((Ra/Ro)) - ((Rb/Ro)) where C is an arbitrary positive dimensionless constant larger than zero, eT being defined by et -At + B where, A is a positive constant per degree Kelvin but otherwise dimensionless, and B is a positive dimensionless constant.
Claim 21
Dependent Claim
15 words
The invention as defined in claim 19, wherein said first resistor is made of nickel.
Claim 22
Dependent Claim
108 words
The invention as defined in claim 1, wherein said variable gain means includes an input junction, an amplifier having an inverting input lead connected from said input junction, and an output lead, first means providing resistance connected from said variable gain means input lead to said input junction, said first temperature sensor including a temperature sensitive first resistor having first and second leads, second means connecting said input junction to said first lead of said first resistor, first branch means for connecting said second lead of said first resistor to said amplifier output lead, and means connecting said amplifier output lead to said variable gain means output lead.
Claim 23
Dependent Claim
135 words
The invention as defined in claim 21, wherein a second temperature sensor is also provided which is adapted to be mounted in proximity to said one material, said first branch means including a single-pole, double-throw switch having a pole and first and second contacts, means connecting said second lead of said first resistor to said first contact, means connecting said pole to said amplifier output lead, means providing temperature insensitive resistance connected from said input junction to said second contact, and means connected from said second temperature sensor for moving said pole into engagement with said second contact when the temperature of said second temperature sensor is below a predetermined temperature and for moving said pole into engagement with said first contact when the temperature of said second temperature sensor is above said predetermined temperature.
Claim 24
Dependent Claim
15 words
The invention as defined in claim 22, wherein said first resistor is made of nickel.
Claim 25
Dependent Claim
144 words
The invention as defined in claim 22, wherein said first resistor has a first resistance which is a function of temperature in degrees Kelvin, said first resistance being approximately equal to R(t) where, R(t) Rof(t), and Ro is the resistance of said first resistor at a temperature t to, said first means having an equivalent series resistance equal to Ra, the sum of the equivalent series resistances of said first branch means and said second means being equal to Rb, said first resistor, said first branch means, and said first and second means being constructed in a manner such that f(t) ((C/-At + B))((Ra/Ro)) - ((Rb/Ro)) where C is an arbitrary positive dimensionless constant larger than zero, et being defined by et -At + B where, A is a positive constant per degree Kelvin but otherwise dimensionless, and B is a positive dimensionless constant.
Claim 26
Dependent Claim
15 words
The invention as defined in claim 24, wherein said first resistor is made of nickel.
Claim 27
Dependent Claim
15 words
The invention as defined in claim 21, wherein said first resistor is made of nickel.
Claim 28
Dependent Claim
144 words
The invention as defined in claim 21, wherein said first resistor has a first resistance which is a function of temperature in degrees Kelvin, said first resistance being approximately equal to R(t) where, R(t) Rof(t), and Ro is the resistance of said first resistor at a temperature t to, said first means having an equivalent series resistance equal to Ra, the sum of the equivalent series resistances of said first branch means and said second means being equal to Rb, said first resistor, said first branch means, and said first and second means being constructed in a manner such that f(t) ((C/-At + B))((Ra/Ro)) - ((Rb/Ro)) where C is an arbitrary positive dimensionless constant larger than zero, et being defined by et -At + B where, A is a positive constant per degree Kelvin but otherwise dimensionless, and B is a positive dimensionless constant.
Claim 29
Dependent Claim
15 words
The invention as defined in claim 27, wherein said first resistor is made of nickel.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |