WO2011152776A1 - Temperature measurement system and method for a temperature measurement system comprising at least one thermocouple - Google Patents

Temperature measurement system and method for a temperature measurement system comprising at least one thermocouple Download PDF

Info

Publication number
WO2011152776A1
WO2011152776A1 PCT/SE2011/050655 SE2011050655W WO2011152776A1 WO 2011152776 A1 WO2011152776 A1 WO 2011152776A1 SE 2011050655 W SE2011050655 W SE 2011050655W WO 2011152776 A1 WO2011152776 A1 WO 2011152776A1
Authority
WO
WIPO (PCT)
Prior art keywords
temperature
temperature measurement
measurement system
thermocouple
ref
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.)
Ceased
Application number
PCT/SE2011/050655
Other languages
French (fr)
Inventor
Ola Stenlåås
Fredrik STRÅÅT
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Scania CV AB
Original Assignee
Scania CV AB
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Scania CV AB filed Critical Scania CV AB
Publication of WO2011152776A1 publication Critical patent/WO2011152776A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K15/00—Testing or calibrating of thermometers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N11/00—Monitoring or diagnostic devices for exhaust-gas treatment apparatus
    • F01N11/002—Monitoring or diagnostic devices for exhaust-gas treatment apparatus the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/22—Safety or indicating devices for abnormal conditions
    • F02D41/222—Safety or indicating devices for abnormal conditions relating to the failure of sensors or parameter detection devices
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K15/00—Testing or calibrating of thermometers
    • G01K15/007—Testing
    • 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
    • G01K7/02—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using thermoelectric elements, e.g. thermocouples
    • 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
    • G01K7/02—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using thermoelectric elements, e.g. thermocouples
    • G01K7/10—Arrangements for compensating for auxiliary variables, e.g. length of lead
    • G01K7/12—Arrangements with respect to the cold junction, e.g. preventing influence of temperature of surrounding air
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N2560/00—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics
    • F01N2560/06—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being a temperature sensor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K2205/00—Application of thermometers in motors, e.g. of a vehicle
    • G01K2205/04—Application of thermometers in motors, e.g. of a vehicle for measuring exhaust gas temperature
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/40—Engine management systems

Definitions

  • Temperature measurement system and method for a temperature measurement system comprising at least one thermocouple.
  • the present invention relates to a system and a method according to the preambles of the independent claims.
  • OBD on board diagnosis
  • OBD OBD is used to investigate the status of a vehicle.
  • the electrical socket used has 16 poles and has to be readily accessible from the driving seat.
  • any error codes can be read and service lamps be switched off. Real-time data may also be read.
  • thermocouples are a type of temperature sensor consisting of two mutually insulated metal wires made of different materials. At one end, the measuring point (often called "hot junction"), the two wires are joined together so that they have electrical contact with one another. At the other end they are connected to an instrument for measurement of electrical voltage.
  • thermoelectric voltage Seebeck voltage
  • thermocouple The voltage from a thermocouple is small (typically a few thousand microvolts per degree of temperature difference) so the measuring instrument needs to be sensitive.
  • Thermocouples are made of various standard materials. In many cases the material characteristics are so good that it is possible to assume a simple linear relationship between voltage and temperature. This relationship is usually called the Seebeck coefficient.
  • thermocouple The most commonly used type of thermocouple is the type wire thermocouple which comprises two conductors, viz. chromel (a nickel-chrome alloy) and alumel (a nickel- aluminium alloy). At around room temperature the electromotive voltage for the chromel/alumel combination is about 41 ⁇ /° €.
  • Thermocouples generally provide an accurate temperature measurement, are robust and have a quick response time. There are various different ways of determining the temperature in the measuring instrument, i.e. at the cold junction. One way is to use a thermistor, i.e. a temperature-dependent resistor, placed close to the cold junction. Another way is described in EP 1,087,217, in which a temperature-sensitive transistor is used instead. US 3,91 1,745 describes a thermocouple which comprises a resistor with a temperature- dependent resistance which is used to compensate for temperature changes at the cold junction.
  • thermocouple's temperature measurement is based on the temperature difference between the hot and cold junctions
  • the reliability of the measurement depends inter alia on how accurate the measurement of the temperature at the cold junction is.
  • the prior art described above indicates various different methods for determining the temperature at the cold junction which all have the disadvantage that if an incorrect temperature value for the cold junction has been measured, e.g. because the temperature sensor is faulty or damaged, the thermocouple will deliver an incorrect temperature.
  • the object of the present invention is to indicate a system and a method which give an indication if there is such an error.
  • the invention thus covers a temperature measurement system comprising at least one thermocouple with a measuring portion and a reference portion which presents a reference temperature T RE F for the thermocouple.
  • the system comprises also a temperature measurement circuit adapted to determining the temperature difference between the measuring portion and the reference portion and to determining on the basis thereof the temperature for the measuring portion.
  • the invention covers also a method for a temperature measurement system which comprises at least one thermocouple with a measuring portion and a reference portion which presents a reference temperature T RE F for the thermocouple.
  • the method comprises:
  • thermocouple determining the reference temperature T REF for the thermocouple
  • An advantage of the present invention is that components already present may be used for diagnosis without having to incorporate new components in the system.
  • Figure 1 is a schematic block diagram of the temperature measurement system according to the present invention.
  • Figure 2 is a schematic block diagram of a temperature measurement circuit according to the present invention.
  • Figure 3 is a flowchart illustrating the method according to the present invention.
  • Figure 1 is a schematic block diagram of the temperature measurement system according to the present invention which comprises at least one thermocouple with a measuring portion 2 and a reference portion 4 which presents a reference temperature TREF for the thermocouple.
  • the system further comprises a temperature measurement circuit 6 adapted to determining the temperature difference between the measuring portion and the reference portion and to determining on the basis thereof the temperature for the measuring portion.
  • the temperature sensor may for example take the form of a thermistor, e.g. of NTC type.
  • the system is adapted to being situated close to a vehicle's exhaust system.
  • the system preferably comprises three thermocouples which share a common reference portion. Within the scope of the concept of the invention, more or fewer thermocouples may be provided depending on the particular application.
  • the three measuring portions are situated along the vehicle's exhaust pipe, e.g. close to the vehicle's catalyst. Providing three measuring portions and doing measurements between pairs of them results in a simple indication as to whether any of them deliver deviating values, i.e. an indication that the respective measuring portion functions correctly.
  • the temperature may range between -40 and 800°C, and more specifically between 150 and 600°C.
  • the temperature sensor 8 and the calculation unit 10 are preferably located in a microprocessor 14 situated close to the temperature measurement circuit 6. The microprocessor thus receives measurement signals from the temperature measurement circuit 6 and does any further processing of the signals before delivering measured data to a general bus system (not depicted).
  • the temperature measurement circuit 6, the reference portion 4 and the microprocessor with the temperature sensor 8 and the calculation unit 10 are located, according to a preferred embodiment, on an assembly unit 16 with a maximum dimension of the order of 50 mm.
  • the assembly unit takes the form of an enclosed unit adapted to being fitted close to the vehicle's exhaust system. Embodiments whose maximum dimension exceeds 50mm are of course also possible within the scope of the concept of the invention indicated in the claims.
  • the assembly unit may be of elongate shape with a length exceeding 50 mm to suit the particular space in which it is to be fitted.
  • the measurement to validate the thermocouple may be done partly at vehicle start-up when the exhaust temperature is relatively low and the microprocessor has not yet been warmed by its own energy consumption. It is also possible to perform measurements during normal operation, in which case the energy consumption of the microprocessor and the heat generated by it have to be taken into account. However, this makes no substantial difference to the measurement, as the temperature measurement system provides reliable diagnosis signals even in that case.
  • Figure 2 is a schematic block diagram of a microprocessor according to the present invention.
  • two threshold levels T T HI, TTH2 are applied. If the absolute value for ⁇ exceeds the lower threshold level T TH i, a first diagnosis signal indicating a minor deviation between the temperatures T REF and T OBD is generated, and if the absolute value for ⁇ exceeds the larger threshold level T T H2, a second diagnosis signal indicating a major deviation between the temperatures T REF and T OBD is generated.
  • T TH I may be set between +10 and + 40°C, e.g. at 20° C.
  • TT H 2 may be set between +80 and + 200°C, e.g. at 120° C.
  • the threshold levels may of course be set elsewhere within the above ranges, depending on the preferred application for measurement of exhaust temperatures.
  • diagnosis signal may depend directly on the absolute value of ⁇ , e.g. ⁇ may be indicated directly by the diagnosis signal.
  • the invention also covers a method for a temperature measurement system which comprises at least one thermocouple with a measuring portion 2 and a reference portion 4 which presents a reference temperature T REF for the thermocouple. The method will now be described with reference to Figure 3.
  • the method comprises:
  • thermocouple determining the reference temperature T REF for the thermocouple
  • the method further comprises determining the temperature difference between the measuring portion and reference portion and determining on the basis thereof the temperature for the measuring portion.
  • the method comprises using two threshold levels (T JHI , T TH 2) and if the absolute value for ⁇ exceeds the lower threshold level T T HI, a first diagnosis signal indicating a minor deviation between the temperatures T RE F and TOBD is generated, and if the absolute value for ⁇ exceeds the larger threshold level T TH2 , a second diagnosis signal indicating a major deviation between the temperatures T REF and TO BD is generated.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Measuring Temperature Or Quantity Of Heat (AREA)

Abstract

Temperature measurement system comprising at least one thermocouple with a measuring portion (2) and a reference portion (4) which presents a reference temperature TREF for the thermocouple, which system comprises a temperature measurement circuit (6) adapted to determining the temperature difference between the measuring portion and the reference portion and to determining on the basis thereof the temperature for the measuring portion. The system comprises, a temperature sensor (8) situated close to the reference portion and adapted to measuring a spot temperature TOBD, and the system further comprises a calculation unit ( 10) adapted to calculating ΔΤ = TREF - T0BD, to comparing the absolute value of ΔΤ with one or more predetermined threshold levels (TTHI, TTH2) and to generating a diagnosis signal ( 12) according to the result of the comparison.

Description

Title
Temperature measurement system and method for a temperature measurement system comprising at least one thermocouple. Field of the invention
The present invention relates to a system and a method according to the preambles of the independent claims.
Background to the invention
An EU standard introduced in 1996 which applies from 2000 to all vehicles with petrol engines and also from 2003 to diesel-engined vehicles requires inter alia that all sensors relevant to emissions be diagnosable for errors. New requirements within the performance field also require that small errors of sensors be detectable. This is done by what is known as "on board diagnosis" (OBD).
As the term indicates, OBD is used to investigate the status of a vehicle. The electrical socket used has 16 poles and has to be readily accessible from the driving seat. When some form of reading unit is connected, any error codes can be read and service lamps be switched off. Real-time data may also be read.
Ensuring that legal requirements about emissions are complied with involves inter alia measuring the temperature in the exhaust system of a vehicle, e.g. a bus or truck. A type of temperature sensor used is so-called thermocouples. A thermocouple is a type of temperature sensor consisting of two mutually insulated metal wires made of different materials. At one end, the measuring point (often called "hot junction"), the two wires are joined together so that they have electrical contact with one another. At the other end they are connected to an instrument for measurement of electrical voltage.
When a metal wire passes through a temperature difference, a thermoelectric voltage (Seebeck voltage) occurs across it. Its hot and cold ends will then acquire different electrical potentials depending on the temperature difference but also partly on the absolute temperatures at the two ends. Different materials produce different voltages. Taking two wires of different materials and joining them together at the measuring point (at which they thus assume the same potential) therefore results in a potential difference between the two ends which is measurable by the measuring instrument. If the temperature in the measuring instrument (often called "cold junction") is known and the relationship between temperature difference and voltage for the two materials is known, it is possible to use a formula to calculate the temperature at the measuring point, a calculation which is catered for by the measuring instrument.
The voltage from a thermocouple is small (typically a few thousand microvolts per degree of temperature difference) so the measuring instrument needs to be sensitive.
Thermocouples are made of various standard materials. In many cases the material characteristics are so good that it is possible to assume a simple linear relationship between voltage and temperature. This relationship is usually called the Seebeck coefficient.
The most commonly used type of thermocouple is the type wire thermocouple which comprises two conductors, viz. chromel (a nickel-chrome alloy) and alumel (a nickel- aluminium alloy). At around room temperature the electromotive voltage for the chromel/alumel combination is about 41 μν/°€.
Thermocouples generally provide an accurate temperature measurement, are robust and have a quick response time. There are various different ways of determining the temperature in the measuring instrument, i.e. at the cold junction. One way is to use a thermistor, i.e. a temperature- dependent resistor, placed close to the cold junction. Another way is described in EP 1,087,217, in which a temperature-sensitive transistor is used instead. US 3,91 1,745 describes a thermocouple which comprises a resistor with a temperature- dependent resistance which is used to compensate for temperature changes at the cold junction.
There are thus various different ways of measuring the temperature at the cold junction and compensating for any temperature changes at the cold junction.
As the thermocouple's temperature measurement is based on the temperature difference between the hot and cold junctions, the reliability of the measurement depends inter alia on how accurate the measurement of the temperature at the cold junction is. The prior art described above indicates various different methods for determining the temperature at the cold junction which all have the disadvantage that if an incorrect temperature value for the cold junction has been measured, e.g. because the temperature sensor is faulty or damaged, the thermocouple will deliver an incorrect temperature.
The object of the present invention is to indicate a system and a method which give an indication if there is such an error. Summary of the invention
The above object is achieved by the invention defined by the independent claims.
Preferred embodiments are defined by the dependent claims.
The invention thus covers a temperature measurement system comprising at least one thermocouple with a measuring portion and a reference portion which presents a reference temperature TREF for the thermocouple. The system comprises also a temperature measurement circuit adapted to determining the temperature difference between the measuring portion and the reference portion and to determining on the basis thereof the temperature for the measuring portion. In addition, a temperature sensor situated close to the reference portion is adapted to measuring a spot temperature TOBD, and the system further comprises a calculation unit adapted to calculating ΔΤ = TREF - T0BD, to comparing the absolute value of ΔΤ with one or more predetermined threshold levels and to generating a diagnosis signal according to the result of the comparison. The invention covers also a method for a temperature measurement system which comprises at least one thermocouple with a measuring portion and a reference portion which presents a reference temperature TREF for the thermocouple.
The method comprises:
determining the reference temperature TREF for the thermocouple;
determining a spot temperature TOBD by means of a temperature sensor situated close to the reference portion;
calculating ΔΤ = TREF - T0BD;
comparing the absolute value of ΔΤ with one or more predetermined threshold levels, and generating a diagnosis signal according to the result of the comparison.
An advantage of the present invention is that components already present may be used for diagnosis without having to incorporate new components in the system.
Brief description of the drawings
Figure 1 is a schematic block diagram of the temperature measurement system according to the present invention.
Figure 2 is a schematic block diagram of a temperature measurement circuit according to the present invention.
Figure 3 is a flowchart illustrating the method according to the present invention.
Detailed description of preferred embodiments of the invention
The invention is described below in more detail with reference to the drawings.
Figure 1 is a schematic block diagram of the temperature measurement system according to the present invention which comprises at least one thermocouple with a measuring portion 2 and a reference portion 4 which presents a reference temperature TREF for the thermocouple. The system further comprises a temperature measurement circuit 6 adapted to determining the temperature difference between the measuring portion and the reference portion and to determining on the basis thereof the temperature for the measuring portion.
A temperature sensor 8 is provided close to the reference portion and is adapted to measuring a spot temperature TQBD, and the system further comprises a calculation unit 10 adapted to calculating ΔΤ = TREF - T0BD, to comparing the absolute value of ΔΤ with one or more predetermined threshold levels TTHi, TTH2 (not depicted in Figure 1) and to generating a diagnosis signal 12 according to the result of the comparison. The temperature sensor may for example take the form of a thermistor, e.g. of NTC type. According to a preferred embodiment, the system is adapted to being situated close to a vehicle's exhaust system. The system preferably comprises three thermocouples which share a common reference portion. Within the scope of the concept of the invention, more or fewer thermocouples may be provided depending on the particular application.
In the preferred case, the three measuring portions are situated along the vehicle's exhaust pipe, e.g. close to the vehicle's catalyst. Providing three measuring portions and doing measurements between pairs of them results in a simple indication as to whether any of them deliver deviating values, i.e. an indication that the respective measuring portion functions correctly. In this application, the temperature may range between -40 and 800°C, and more specifically between 150 and 600°C. The temperature sensor 8 and the calculation unit 10 are preferably located in a microprocessor 14 situated close to the temperature measurement circuit 6. The microprocessor thus receives measurement signals from the temperature measurement circuit 6 and does any further processing of the signals before delivering measured data to a general bus system (not depicted). The temperature measurement circuit 6, the reference portion 4 and the microprocessor with the temperature sensor 8 and the calculation unit 10 are located, according to a preferred embodiment, on an assembly unit 16 with a maximum dimension of the order of 50 mm. The assembly unit takes the form of an enclosed unit adapted to being fitted close to the vehicle's exhaust system. Embodiments whose maximum dimension exceeds 50mm are of course also possible within the scope of the concept of the invention indicated in the claims. For example, the assembly unit may be of elongate shape with a length exceeding 50 mm to suit the particular space in which it is to be fitted.
The measurement to validate the thermocouple may be done partly at vehicle start-up when the exhaust temperature is relatively low and the microprocessor has not yet been warmed by its own energy consumption. It is also possible to perform measurements during normal operation, in which case the energy consumption of the microprocessor and the heat generated by it have to be taken into account. However, this makes no substantial difference to the measurement, as the temperature measurement system provides reliable diagnosis signals even in that case.
An embodiment of the invention is described below with reference to Figure 2, which is a schematic block diagram of a microprocessor according to the present invention.
According to this embodiment, two threshold levels TTHI, TTH2 are applied. If the absolute value for ΔΤ exceeds the lower threshold level TTHi, a first diagnosis signal indicating a minor deviation between the temperatures TREF and TOBD is generated, and if the absolute value for ΔΤ exceeds the larger threshold level TTH2, a second diagnosis signal indicating a major deviation between the temperatures TREF and TOBD is generated.
For example, TTH I may be set between +10 and + 40°C, e.g. at 20° C.
For example, TTH2 may be set between +80 and + 200°C, e.g. at 120° C.
The threshold levels may of course be set elsewhere within the above ranges, depending on the preferred application for measurement of exhaust temperatures.
More than two threshold levels may also be used. Alternatively, the diagnosis signal may depend directly on the absolute value of ΔΤ, e.g. ΔΤ may be indicated directly by the diagnosis signal. The invention also covers a method for a temperature measurement system which comprises at least one thermocouple with a measuring portion 2 and a reference portion 4 which presents a reference temperature TREF for the thermocouple. The method will now be described with reference to Figure 3.
The method comprises:
determining the reference temperature TREF for the thermocouple;
determining a spot temperature TOBD by means of a temperature sensor situated close to the reference portion;
calculating ΔΤ = TREF - T0BD;
comparing the absolute value of ΔΤ with one or more predetermined threshold levels TTH, and
generating a diagnosis signal according to the result of the comparison. If the absolute value for ΔΤ is smaller than the threshold level TTH, the measurement is deemed correct, i.e. the reference temperature is correctly stated. The method further comprises determining the temperature difference between the measuring portion and reference portion and determining on the basis thereof the temperature for the measuring portion.
According to a further embodiment, the method comprises using two threshold levels (TJHI, TTH2) and if the absolute value for ΔΤ exceeds the lower threshold level TTHI, a first diagnosis signal indicating a minor deviation between the temperatures TREF and TOBD is generated, and if the absolute value for ΔΤ exceeds the larger threshold level TTH2, a second diagnosis signal indicating a major deviation between the temperatures TREF and TOBD is generated.
The present invention is not confined to the preferred embodiments described above. Sundry alternatives, modifications and equivalents may be used. The above embodiments are therefore not to be regarded as limiting the invention's protective scope which is defined by the attached claims.

Claims

Claims
1. A temperature measurement system comprising at least one thermocouple with a measuring portion (2) and a reference portion (4) which presents a reference temperature T EF for the thermocouple, which system further comprises a temperature measurement circuit (6) adapted to determining the temperature difference between the measuring portion and the reference portion and to determining on the basis thereof the temperature for the measuring portion,
c h a r a c t e r i s e d in that the system comprises a temperature sensor (8) situated close to the reference portion and adapted to measuring a spot temperature T0BD, and the system further comprises a calculation unit (10) adapted to calculating ΔΤ = TREF - 0BD, to comparing the absolute value of ΔΤ with one or more predetermined threshold levels (TTH, TTH I , TJH2) and to generating a diagnosis signal (12) according to the result of the comparison.
2. A temperature measurement system according to claim 1 , in which the temperature sensor (8) and the calculation unit ( 10) are located in a microprocessor ( 14).
3. A temperature measurement system according to claim 1 or 2, which system comprises three thermocouples with a shared reference portion.
4. A temperature measurement system according to any one of the foregoing claims, which system is adapted to being situated close to a vehicle's exhaust system.
5. A temperature measurement system according to any one of the foregoing claims, in which the temperature measurement circuit (6), the reference portion (4) and the temperature sensor (8) are located on an assembly unit (16) whose maximum dimension is 50 mm.
6. A temperature measurement system according to any one of the foregoing claims, in which the temperature sensor is a thermistor.
7. A temperature measurement system according to claim 6, in which the thermistor is of NTC type.
8. A temperature measurement system according to any one of the foregoing claims, in which two threshold levels (TJHI , TJH2) are applied and if the absolute value for ΔΤ exceeds the lower threshold level TTHI, a first diagnosis signal indicating a minor deviation between the temperatures TREF and TOBD is generated, and if the absolute value for ΔΤ exceeds the larger threshold level TTH2, a second diagnosis signal indicating a major deviation between the temperatures TREF and TOBD is generated.
9. A method for a temperature measurement system comprising at least one thermocouple with a measuring portion (2) and a reference portion (4) which presents a reference temperature TREF for the thermocouple, c h a r a c t e r i s e d in that the method comprises:
determining the reference temperature TREF for the thermocouple;
determining a spot temperature TOBD by means of a temperature sensor situated close to the reference portion;
calculating ΔΤ = TREF - TOBD;
comparing the absolute value of ΔΤ with one or more predetermined threshold levels, and generating a diagnosis signal (12) according to the result of the comparison.
10. A method according to claim 9, which method comprises:
determining the temperature difference between the measuring portion and the reference portion and determining on the basis thereof the temperature for the measuring portion.
1 1. A method according to either of claims 9 and 10, which method comprises: using two threshold levels (TTm, xm) and if the absolute value of ΔΤ exceeds the lower threshold level TJHI, a first diagnosis signal indicating a minor deviation between the temperatures TREF and TOBD is generated, and if the absolute value for ΔΤ exceeds the larger threshold level TTH2, a second diagnosis signal indicating a major deviation between the temperatures TREF and TQBD is generated.
PCT/SE2011/050655 2010-06-01 2011-05-26 Temperature measurement system and method for a temperature measurement system comprising at least one thermocouple Ceased WO2011152776A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE1050545-1 2010-06-01
SE1050545A SE534904C2 (en) 2010-06-01 2010-06-01 Temperature measurement system and method for a temperature measurement system comprising at least one thermocouple

Publications (1)

Publication Number Publication Date
WO2011152776A1 true WO2011152776A1 (en) 2011-12-08

Family

ID=45066972

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE2011/050655 Ceased WO2011152776A1 (en) 2010-06-01 2011-05-26 Temperature measurement system and method for a temperature measurement system comprising at least one thermocouple

Country Status (2)

Country Link
SE (1) SE534904C2 (en)
WO (1) WO2011152776A1 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105987774A (en) * 2015-03-18 2016-10-05 恩德莱斯+豪瑟尔韦泽尔有限商业两合公司 A thermo wire testing circuit
FR3042861A1 (en) * 2015-10-26 2017-04-28 Valeo Systemes De Controle Moteur TEMPERATURE SENSOR FOR A MOTOR VEHICLE COMPRISING A THERMOCOUPLE
EP3346524A1 (en) * 2017-01-09 2018-07-11 Samsung SDI Co., Ltd Battery module with thermocouple unit
EP3534125A1 (en) * 2018-02-28 2019-09-04 CPT Group GmbH Electric device comprising a printed circuit board and method for determining local temperatures at different measurement points of the printed circuit board
CN114544021A (en) * 2022-01-13 2022-05-27 成都金知丽科技有限公司 Cold end temperature estimation method of multi-channel temperature acquisition system based on heat conduction and signal reconstruction
CN115095418A (en) * 2022-06-17 2022-09-23 江铃汽车股份有限公司 Exhaust system hot end evaluation method and system

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4157663A (en) * 1978-04-25 1979-06-12 The Boeing Company Automatic thermocouple reference junction compensator
US4588308A (en) * 1983-09-02 1986-05-13 Nissan Motor Co., Ltd. Temperature measuring device with thermocouple
US4590472A (en) * 1982-12-01 1986-05-20 General Electric Company Analog signal conditioner for thermal coupled signals
EP0686835A1 (en) * 1994-06-07 1995-12-13 Fluke Corporation Compact thermocouple connector
US5611624A (en) * 1993-02-10 1997-03-18 Siemens Aktiengesellschaft Device and method for digitally measuring a voltage varying within a given range, and uses thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4157663A (en) * 1978-04-25 1979-06-12 The Boeing Company Automatic thermocouple reference junction compensator
US4590472A (en) * 1982-12-01 1986-05-20 General Electric Company Analog signal conditioner for thermal coupled signals
US4588308A (en) * 1983-09-02 1986-05-13 Nissan Motor Co., Ltd. Temperature measuring device with thermocouple
US5611624A (en) * 1993-02-10 1997-03-18 Siemens Aktiengesellschaft Device and method for digitally measuring a voltage varying within a given range, and uses thereof
EP0686835A1 (en) * 1994-06-07 1995-12-13 Fluke Corporation Compact thermocouple connector

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105987774A (en) * 2015-03-18 2016-10-05 恩德莱斯+豪瑟尔韦泽尔有限商业两合公司 A thermo wire testing circuit
US10209143B2 (en) 2015-03-18 2019-02-19 Endress + Hauser Wetzer Gmbh + Co. Kg Thermo wire testing circuit
FR3042861A1 (en) * 2015-10-26 2017-04-28 Valeo Systemes De Controle Moteur TEMPERATURE SENSOR FOR A MOTOR VEHICLE COMPRISING A THERMOCOUPLE
EP3346524A1 (en) * 2017-01-09 2018-07-11 Samsung SDI Co., Ltd Battery module with thermocouple unit
EP3534125A1 (en) * 2018-02-28 2019-09-04 CPT Group GmbH Electric device comprising a printed circuit board and method for determining local temperatures at different measurement points of the printed circuit board
CN114544021A (en) * 2022-01-13 2022-05-27 成都金知丽科技有限公司 Cold end temperature estimation method of multi-channel temperature acquisition system based on heat conduction and signal reconstruction
CN115095418A (en) * 2022-06-17 2022-09-23 江铃汽车股份有限公司 Exhaust system hot end evaluation method and system
CN115095418B (en) * 2022-06-17 2023-10-27 江铃汽车股份有限公司 Hot end evaluation method and system for exhaust system

Also Published As

Publication number Publication date
SE1050545A1 (en) 2011-12-02
SE534904C2 (en) 2012-02-14

Similar Documents

Publication Publication Date Title
US5887978A (en) Self-verifying temperature sensor
EP3109607B1 (en) Method for temperature drift compensation of temperature measurement device using thermocouple
CN102369422B (en) Thermocouple temperature sensor with connection detection circuitry
WO2011152776A1 (en) Temperature measurement system and method for a temperature measurement system comprising at least one thermocouple
JP5491889B2 (en) Energization control device for vehicle control parts
JP2012522247A5 (en)
JP2002318162A (en) Abnormality detection method and protection device, and temperature estimation method and estimation device
US12072248B2 (en) Thermometer having a diagnostic function
US11187592B2 (en) Thermocouple arrangement and method for measuring temperatures
US11221257B2 (en) Temperature probe
US8326568B2 (en) Temperature sensor and temperature sensing method
US12601644B2 (en) Thermometer with a diagnostic function
CN102183437B (en) On-board method and system for monitoring onset of rapid oil oxidation and sludge formation in engine oils
RU2376644C2 (en) Fire alarm system with linear detectors, based on merging data, and method of making said alarm
US6983223B2 (en) Detecting thermocouple failure using loop resistance
JP2001188547A (en) Calibration method of temperature sensor
CN118129948A (en) A method and device for determining output temperature of a temperature sensor
US12480825B2 (en) Thermometer having a diagnostic function
JP7183093B2 (en) gas calibration device
EP2729777B1 (en) Method for testing temperature sensors and a testing device
RU2789611C1 (en) Method for determining the reliability of the measurement results of a thermoelectric converter
JPH0540533A (en) Electronic device temperature detection system
JP2004150836A (en) Correction method and correction circuit for cold junction compensation in thermocouple input of programmable controller
Szpytko et al. Telematics based concept focused to avoid engine and vehicle trouble due to overheating
CN119197822A (en) A method for detecting fault of vehicle engine water temperature sensor

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11790080

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 11790080

Country of ref document: EP

Kind code of ref document: A1