DE2460648A1 - Platinum resistance temp measurement linearisation circuit - operational amplifier injects reference voltage dependent current - Google Patents
Platinum resistance temp measurement linearisation circuit - operational amplifier injects reference voltage dependent currentInfo
- Publication number
- DE2460648A1 DE2460648A1 DE19742460648 DE2460648A DE2460648A1 DE 2460648 A1 DE2460648 A1 DE 2460648A1 DE 19742460648 DE19742460648 DE 19742460648 DE 2460648 A DE2460648 A DE 2460648A DE 2460648 A1 DE2460648 A1 DE 2460648A1
- Authority
- DE
- Germany
- Prior art keywords
- platinum resistance
- voltage
- temperature
- digital
- reference voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
- G01K7/16—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements
- G01K7/18—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a linear resistance, e.g. platinum resistance thermometer
- G01K7/20—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a linear resistance, e.g. platinum resistance thermometer in a specially-adapted circuit, e.g. bridge circuit
- G01K7/21—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a linear resistance, e.g. platinum resistance thermometer in a specially-adapted circuit, e.g. bridge circuit for modifying the output characteristic, e.g. linearising
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B11/00—Automatic controllers
- G05B11/01—Automatic controllers electric
- G05B11/32—Automatic controllers electric with inputs from more than one sensing element; with outputs to more than one correcting element
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D23/00—Control of temperature
- G05D23/19—Control of temperature characterised by the use of electric means
- G05D23/20—Control of temperature characterised by the use of electric means with sensing elements having variation of electric or magnetic properties with change of temperature
- G05D23/24—Control of temperature characterised by the use of electric means with sensing elements having variation of electric or magnetic properties with change of temperature the sensing element having a resistance varying with temperature, e.g. a thermistor
Abstract
Description
Schaltungsanordnung zur Messung von Temperatur mit einem Platin - Widerstandsthermometer in linearem Zusammenhang mit einer elektrischen Ausgangsgröße.Circuit arrangement for measuring temperature with a platinum Resistance thermometer in a linear relationship with an electrical output variable.
Die Erfindung betrifft zwei Vorrichtungen, die als elektrisches Thermometer und als Teil von Temperaturreglern und Prozesselementen Anwendung fingden.The invention relates to two devices that act as an electrical thermometer and used as part of temperature controllers and process elements.
Lls bekannt gilt: Aufwendige Hardwarelösungen mit nichtlinearen Schaltungselementen, digitale Harwarelösungen mit Analog - Digitalwandlern und Festwertspeichern, Softwarelösungen in EDV - Anlagen.As is well known, the following applies: Complex hardware solutions with non-linear circuit elements, digital hardware solutions with analog-digital converters and read-only memories, software solutions in IT systems.
Die genannten Lösungen sind sehr aufwendig.The solutions mentioned are very complex.
Dem Bekannten gegenüber soll die Linearisierung nach der Erfindung durch eine einfache Schaltungsanordnung realisiert werden.In relation to what is known, the linearization according to the invention is intended can be realized by a simple circuit arrangement.
Das Temperaturverhalten des Platinwiderstandes läßt sich näherung weise durch die folgenden Differentiale für kleine Ströme charakterisieren: d3R dT3 Zwei Schaltungsanordnungen zum Erreichen des linearen Temperatur-Spannungszusammenhanges. sind erfindungsgemäß dadurch gekennzeichnet, daß sie nur jeweils einen linearen Operationsverstärker be -notigen, der als Stromquelle dem als Temperaturfühler wirkenden Platinwiderstand einen Strom so einprägt, daß dieser etwas mit dem Vert des Platinwiderstandes ansteigt. Solchermaßen läßt sich erreichen, daß die Spannung am Platinwiderstand mit guter Näherung linear von seiner Temperatur abhängt0 Die Erfindung wird anhand zweier Figuren, die die wesentlichen Schaltungsmerkmale zeigen, näher erläutert.The temperature behavior of the platinum resistor can be approximately characterized by the following differentials for small currents: d3R dT3 Two circuit arrangements to achieve the linear temperature-voltage relationship. are characterized according to the invention in that they each need only one linear operational amplifier which, as a current source, impresses a current on the platinum resistor acting as a temperature sensor in such a way that it rises somewhat with the value of the platinum resistor. In this way it can be achieved that the voltage across the platinum resistor is linearly dependent on its temperature with a good approximation. The invention is explained in more detail with reference to two figures which show the essential circuit features.
Die Figur 1 zeigt die Beschaltung eines Operationsverstärkers ( 1 ) u. a. mit einem Platinwiderstand ( 2 ) und einem Festwider -stand ( 3 ). In der folgenden mathematischen Darstellung sind diese Widerstände als R2 bzw. R3 bezeichnet. Die Spannung Ua an ( 2 ) gehorcbt der Schaltungsanordnung und der Eingangs spannung Ue folgendermaßen: Ua = - Ue a R2/R3 / ( 1 - b ( 1 + R2/R3)) mit U I = - Ue ( at R2 + b R2 ) Die Größen a,b,a',b' sind schaltungsbedingt und konstant, gegeben durch R3 und die unbenannten Widerstände. Diese Schaltungsanordnung bewirkt eine kleine , positive quadratische Korrektur der Spannung Ua mit steigender Temperatur von ( 2 ), sie kompensiert den negativen quadratischen Koeffizienten der Widerstands- Temperaturkurve des Platinwiderstandes.FIG. 1 shows the wiring of an operational amplifier (1) including a platinum resistor (2) and a fixed resistor (3). In the following mathematical representation, these resistances are referred to as R2 and R3. The voltage Ua at (2) belongs to the circuit arrangement and the input voltage Ue as follows: Ua = - Ue a R2 / R3 / (1 - b (1 + R2 / R3)) with UI = - Ue (at R2 + b R2) The quantities a, b, a ', b' are circuit-related and constant, given by R3 and the unnamed resistances. This circuit arrangement causes a small, positive quadratic correction of the voltage Ua with increasing temperature of (2), it compensates for the negative quadratic coefficient of the resistance-temperature curve of the platinum resistor.
Die Figur 2 zeigt die Beschaltung eines Operationsverstärkers ( 4 ) u. a. mit einem platinwiderstand ( 5 ), der in der mathematischen Darstellung als R5 auftaucht. Die Spannung Ua an ( 5 ) gehorcht der Schaltungsanordnung und der Eingangsspannung Ue folgendermaßen: Ua - Ue a R5 / ( 1 - b R5 ) mit |b R5| << 1 gilt s Ua = Ue ( a R5 + b' R52 ) Die Größen a,b,b' sind schaltungsbedingt und konstant. Auch hier ist eine kleine , positive quadratische Korrektur der Spannung U@ lit wachsender Temperatur erreicht.FIG. 2 shows the wiring of an operational amplifier (4 ) and others with a platinum resistor (5), which is shown in the mathematical representation when R5 shows up. The voltage Ua at (5) obeys the circuit arrangement and of the input voltage Ue as follows: Ua - Ue a R5 / (1 - b R5) with | b R5 | << 1 applies s Ua = Ue (a R5 + b 'R52) The quantities a, b, b' are circuit-related and constant. Again, there is a small, positive quadratic correction to the voltage U @ lit increasing temperature reached.
Mit Hilfe eines geeignet dimensionierten Differenzverstärkers der Spannung Ua und einer Hilfsspannung läßt sich eine Spannung U = U ( T ) so gegen das Bezugspotential erzeugen, daß U fUr die snfangstemperatur eines gegebenen Temperaturbereiches verschrin det ( T ist Temperaturgröße ).With the help of a suitably dimensioned differential amplifier the Voltage Ua and an auxiliary voltage can be compared to a voltage U = U (T) generate the reference potential that U is the initial temperature of a given temperature range shrinks (T is temperature variable).
Bei großem Strom durch den Platinwiderstand läßt sich die Eigenerwärmung durch Pulsen der Eingangsspannung Ue reduzieren.With a large current through the platinum resistor, self-heating can be reduced reduce the input voltage Ue by pulsing.
Die Sollgröße der Temperatur eines Temperaturreglers, der durch das erfindungsgemäß linearisierte Platinthermometer gekennzeichnet ist, wird als Spannungswert linear mit der Solltemperatur vorgegeben. Eine Potentiometerschaltung kompensiert in einem solchen Schaltregler die Schwankungen der gemeinsamen Referenzspannung Se.The setpoint value of the temperature of a temperature controller, which is determined by the according to the invention linearized platinum thermometer is characterized as a voltage value specified linearly with the target temperature. A potentiometer circuit compensates in such a switching regulator the fluctuations in the common reference voltage Se.
Ein Digital - Analogwandler als Sollspannungsquelle eines solchen Reglers erlaubt die digitale Vorgabe der Temperatursollgröße, wodurch deren unmittelbare Fiihrung durch Prozessmaschinen möglich ist. Eine, das Temperatur - Zeitverhalten einer solchen Regelung beeinflussende Rückführung kann sowohl analog wie auch digital ausgebildet sein; die im letzten Fall gewonnene Rückführungsgröße läßt sich vorteilhaft dem digitalen Temperatursollwert entweder in einer Prozessmaschine oder in einer, zwischen einem Sollwertgeber und einem Digital - Analogwandler eingefügten Logikschaltung, hinzuaddieren.A digital-to-analog converter as a nominal voltage source of such Controller allows the digital specification of the temperature setpoint, whereby its immediate Leadership through process machines is possible. One, the temperature-time behavior Feedback influencing such a regulation can be both analog and digital be trained; the feedback variable obtained in the latter case can be advantageous the digital temperature setpoint either in a process machine or in a, logic circuit inserted between a setpoint generator and a digital-analog converter, add.
Die Solltemperaturen vieler Regler i ( 6,7,8 ) ganzer Ofensysteme i ( 9 ), dargestellt in der Figur 3, lassen sich, gekennzeichnet durch das erfindungsgemäß linerisierte Platinsiderstandsthermometer ( 6 ), mit einem einzigen Digital - Analogwandler ( 1o ) vorgeben, wenn dieser, programmiert durch eine irgendwie geartete Ablauisteuerung ( 11 ), sequenziell die den Solltemperaturen zugeordneten Sollspannungen den Ist - Sollkomperatoren ( 7 ) der einzelnen Regler ( 6,7,8 ) zuführt. Nach Einschwingen des jeweiagen Ist - Soll-Komperators ( 7 ) wird der zugeordnete Digitalspeicher ( 8 ) getriggert, er gibt eine digitale Richtgröße ( z. B. 1 Bit ) an den zugeordneten Ofen ab.The target temperatures of many controllers i (6,7,8) of entire furnace systems i (9), shown in FIG. 3, can be characterized by the according to the invention linearized platinum resistance thermometer (6), with a single digital - analog converter (1o) if this is programmed by some kind of sequence control (11), the setpoint voltages assigned to the setpoint temperatures sequentially denote the actual - Nominal comparators (7) of the individual controllers (6,7,8) supplies. After settling of the respective actual - target comparator (7) is the assigned digital memory (8) triggered, it gives a digital benchmark (e.g. 1 bit) to the assigned Furnace off.
Claims (6)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19742460648 DE2460648A1 (en) | 1974-12-20 | 1974-12-20 | Platinum resistance temp measurement linearisation circuit - operational amplifier injects reference voltage dependent current |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19742460648 DE2460648A1 (en) | 1974-12-20 | 1974-12-20 | Platinum resistance temp measurement linearisation circuit - operational amplifier injects reference voltage dependent current |
Publications (1)
Publication Number | Publication Date |
---|---|
DE2460648A1 true DE2460648A1 (en) | 1976-06-24 |
Family
ID=5934138
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DE19742460648 Pending DE2460648A1 (en) | 1974-12-20 | 1974-12-20 | Platinum resistance temp measurement linearisation circuit - operational amplifier injects reference voltage dependent current |
Country Status (1)
Country | Link |
---|---|
DE (1) | DE2460648A1 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3231996A1 (en) * | 1982-08-27 | 1984-03-01 | Endress U. Hauser Gmbh U. Co, 7867 Maulburg | RESISTANCE THERMOMETER |
DE19757258C2 (en) * | 1997-12-23 | 2001-02-08 | Heraeus Electro Nite Int | Sensor with temperature-dependent measuring resistor and its use for temperature measurement |
EP2953103A1 (en) * | 2014-06-02 | 2015-12-09 | Siemens Schweiz AG | Danger warning system |
CN111238673A (en) * | 2020-01-06 | 2020-06-05 | 宁波中车时代传感技术有限公司 | Measuring circuit of film temperature sensor |
-
1974
- 1974-12-20 DE DE19742460648 patent/DE2460648A1/en active Pending
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3231996A1 (en) * | 1982-08-27 | 1984-03-01 | Endress U. Hauser Gmbh U. Co, 7867 Maulburg | RESISTANCE THERMOMETER |
EP0101956A2 (en) * | 1982-08-27 | 1984-03-07 | Endress u. Hauser GmbH u.Co. | Resistance thermometer |
EP0101956A3 (en) * | 1982-08-27 | 1985-09-18 | Endress U. Hauser Gmbh U.Co. | Resistance thermometer |
DE19757258C2 (en) * | 1997-12-23 | 2001-02-08 | Heraeus Electro Nite Int | Sensor with temperature-dependent measuring resistor and its use for temperature measurement |
US6232618B1 (en) | 1997-12-23 | 2001-05-15 | Heraeus Electro-Nite International N.V. | Sensor with temperature-dependent measuring resistor and its use for temperature measurement |
EP2953103A1 (en) * | 2014-06-02 | 2015-12-09 | Siemens Schweiz AG | Danger warning system |
CN111238673A (en) * | 2020-01-06 | 2020-06-05 | 宁波中车时代传感技术有限公司 | Measuring circuit of film temperature sensor |
WO2021139128A1 (en) * | 2020-01-06 | 2021-07-15 | 宁波中车时代传感技术有限公司 | Measurement circuit of thin-film temperature sensor |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
DE2746360A1 (en) | Remote thermal monitoring of several locations - uses alternative thermal resistors which switch into branch of resistive bridge | |
DE2917237C2 (en) | ||
DE2648478C2 (en) | Method and device for regulating the air / fuel ratio of an internal combustion engine equipped with an exhaust gas sensor | |
DE2350083A1 (en) | CIRCUIT ARRANGEMENT FOR CORRECTING THE OUTPUT SIGNAL OF A MEASURING DEVICE | |
EP0101956B1 (en) | Resistance thermometer | |
DE2518890B2 (en) | LINEARIZING DEVICE | |
DE1947004A1 (en) | Device for changing the temperature of a sample substance | |
DE2460648A1 (en) | Platinum resistance temp measurement linearisation circuit - operational amplifier injects reference voltage dependent current | |
EP2197117B1 (en) | Switching unit for creating an output voltage depending on a digital data value and method for calibrating the switching unit | |
DE10024716C2 (en) | Transmitter for potentiometric position sensors and method for parameterization | |
EP0204183A1 (en) | Method for calibrating a hot wire air mass flow meter and hot wire air mass flow meter | |
DE2518422A1 (en) | Automatic resistance compensating circuit - used for connections between resistors in bridge branches in measuring instruments | |
DE2447629A1 (en) | Resistance measuring circuit - three wire circuit is used to balance line influences | |
DE10244466C1 (en) | Switching arrangement, for operating linear exhaust gas probe for vehicle engine, comprises first comparison switching, pump current source for preparing current and second switching circuit for comparing voltage on pump cell | |
DE3803104A1 (en) | Circuit arrangement for correcting weak analogue voltages of measurement value transmitters in the case of severe non-linearity | |
EP0333916A2 (en) | Method for the temperature regulation of resistance-heating conductors | |
DE2827208C2 (en) | ||
DE2827601B1 (en) | Method for contactless measurement of direct and alternating currents | |
DE2412226A1 (en) | DIGITAL-ANALOGUE CONVERTER | |
DE2203306C2 (en) | Circuit arrangement for zero point shifting of measuring voltages | |
DE1293834B (en) | Procedure for calibrating analog-to-digital converters | |
DE2455588A1 (en) | Linearizing circuit for NTC resistors esp in thermometers - uses temperature independent resistor for linearity over wide range | |
DE3124231A1 (en) | Arrangement for representing a variable electrical precision resistor | |
DE3313043A1 (en) | Circuit arrangement for measuring a multiplicity of slowly varying operating temperatures | |
DE2452529C3 (en) | Device for the independent setting of the start and end values of an electrical measuring range with a bridge circuit |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
OHJ | Non-payment of the annual fee |