CN108680286B - High-resolution heat flow signal measuring system used under high-magnetic environment wide-temperature area - Google Patents
High-resolution heat flow signal measuring system used under high-magnetic environment wide-temperature area Download PDFInfo
- Publication number
- CN108680286B CN108680286B CN201810723663.4A CN201810723663A CN108680286B CN 108680286 B CN108680286 B CN 108680286B CN 201810723663 A CN201810723663 A CN 201810723663A CN 108680286 B CN108680286 B CN 108680286B
- Authority
- CN
- China
- Prior art keywords
- temperature
- heat flow
- measuring
- signal
- low
- 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.)
- Active
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K17/00—Measuring quantity of heat
- G01K17/06—Measuring quantity of heat conveyed by flowing media, e.g. in heating systems e.g. the quantity of heat in a transporting medium, delivered to or consumed in an expenditure device
- G01K17/08—Measuring quantity of heat conveyed by flowing media, e.g. in heating systems e.g. the quantity of heat in a transporting medium, delivered to or consumed in an expenditure device based upon measurement of temperature difference or of a temperature
Abstract
The invention discloses a high-resolution heat flow signal measuring system used under a high-magnetic environment wide-temperature area, which consists of two paths of constant current source circuits, a heat flow sensor, a low-temperature-drift low-noise amplifier module and a signal measuring circuit, wherein the two paths of constant current source circuits can adjust band feedback, the constant current source circuits supply power to two pairs of symmetrical platinum wire temperature measuring thermal resistors of the heat flow sensor, the temperature difference is calculated through the voltage difference generated by two groups of platinum wire temperature measuring thermal resistors so as to generate a differential thermal signal, the differential thermal signal is amplified through one group of low-temperature-drift low-noise amplifier module, and finally, the differential thermal signal is acquired and measured by a sigma-delta analog-to-digital converter with. Compared with the prior art, the invention has the following characteristics: 1. the heat flow sensor has paramagnetism and is not influenced by a strong magnetic environment. 2: the heat flow sensor has wide temperature measuring range. 3: the heat flow sensor generates a large heat flow signal and has good repeatability. 4: the heat flow signal amplifying module is provided with a magnetic shield and a constant temperature shell, and noise and temperature drift influences are eliminated.
Description
Technical Field
The invention relates to the field of heat flow signal measurement, in particular to a high-resolution heat flow signal measurement system under a high-magnetic environment wide-temperature area.
Background
The magnetic environment can affect the phase formation and performance of the material, and the experiment at the temperature range of 100K to 973K has important scientific value for the research of new phenomena and mechanisms of the material in the high magnetic field environment with the magnetic flux density exceeding 1 Tesla. Therefore, it is very significant to manufacture a thermal analyzer for wide temperature range application in magnetic environment to measure the phase formation and performance of materials.
The most central technique of differential scanning calorimetry is to measure the heat flow signal, which is generated by measuring the temperature difference between the sample temperature and the reference substance. The conventional heat flow signal is measured by reversely connecting two nickel-chromium-constantan thermocouples of the same type, the range of the heat flow signal is between-1000 uV and 1000uV, and the resolution of the signal is required to be within +/-0.05 uV. The magnetic flux range of high magnetic environment is 1-15 tesla, the nickel chromium-constantan thermocouple belongs to ferromagnetic material, and the electric potential generated under the high magnetic environment can produce large deviation, thereby causing the deviation of heat flow signal. If a platinum rhodium 10-platinum paramagnetic material thermocouple is adopted, the influence of a magnetic environment can be eliminated, but the platinum rhodium 10-platinum thermocouple cannot measure the temperature below 200K. Therefore, designing a method for measuring heat flow signals with high resolution under a wide temperature range of a magnetic environment becomes the key of a thermal analyzer of the wide temperature range of the magnetic environment.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a method for measuring a heat flow signal at high resolution in a wide temperature region of a magnetic environment, so that a thermal analyzer can analyze material phenomena and mechanisms in the magnetic environment.
The technical scheme adopted by the invention for solving the problems is as follows:
The high-resolution heat flow signal measuring system used under the high-magnetic environment wide-temperature area comprises two paths of constant current source circuits, a heat flow sensor, a low-temperature drift low-noise amplifier module and a signal measuring circuit, wherein the two paths of constant current source circuits can adjust band feedback, the constant current source circuits supply power to a pair of symmetrical platinum wire temperature measuring thermal resistors of the heat flow sensor, the temperature difference is calculated through the voltage difference generated by two groups of platinum wire temperature measuring thermal resistors, so that a differential heat signal is generated, the differential heat signal is amplified through a group of low-temperature drift low-noise amplifier module, and finally, a sigma-delta analog-digital converter with the high resolution reaching 24 bits is used for collecting and measuring.
Furthermore, the constant current source circuit is composed of a current output circuit, a current regulating circuit and a current collecting circuit, and negative feedback is formed by current collection and current regulation to control the precision of the current output by the constant current source.
Furthermore, the output current of the constant current source circuit is 0.1mA, the output precision is +/-0.0001 mA, and the temperature drift coefficient is less than 20 ppm.
Furthermore, the heat flow sensor is divided into a three-layer structure, namely a bottom layer, a middle layer and a top layer, wherein the bottom layer is composed of a high-thermal-conductivity aluminum nitride substrate, the middle layer is composed of a pair of completely symmetrical platinum wire temperature measurement thermal resistors, the platinum wire temperature measurement thermal resistors are uniformly wound on the ceramic framework, and two inner leads are led out from each pair of platinum wire temperature measurement thermal resistors and are led out from through holes of the substrate; the rest part is filled with high-insulativity and high-thermal conductivity magnesia powder; the top layer adopts a high-temperature glaze sealing layer to realize electric isolation.
Furthermore, the aluminum nitride substrate, the platinum wire temperature measuring thermal resistor, the inner lead, the magnesium oxide powder and the high-temperature glaze sealing layer are all paramagnetic materials.
Furthermore, the circuit part of the low-temperature-drift low-noise amplifier module consists of a differential input circuit, a primary amplification circuit and a secondary amplification circuit, and the shell of the low-temperature-drift low-noise amplifier module is a constant-temperature control metal magnetic shielding assembly.
Furthermore, the constant temperature control metal magnetic shielding assembly consists of a heating belt, heat preservation cotton, a temperature measuring sensor and an external temperature controller, the constant temperature control assembly forms a temperature control loop, and the temperature of the control shell is always in a constant temperature state.
Furthermore, the outer surface layer of the shell of the constant temperature control metal magnetic shielding component adopts a permalloy shielding cover.
The design advantages of the invention are as follows: 1: the heat flow sensor which can be used in a magnetic environment is designed, and the sensor has the advantages of wide measurement and temperature measurement range, high signal precision, high repeatability and high resolution. 2: the constant current source circuit for providing stable work of the heat flow sensor is designed, and the circuit ripple is small. 3: the amplification module for measuring the tiny signal with high resolution is designed, the noise interference of the amplification module is low, and the temperature drift coefficient is low.
Compared with the prior art, the invention has the following characteristics: 1. the heat flow sensor has paramagnetism and is not influenced by a strong magnetic environment. 2: the heat flow sensor has wide temperature measuring range. 3: the heat flow sensor generates a large heat flow signal and has good repeatability. 4: the heat flow signal amplifying module is provided with a magnetic shield and a constant temperature shell, and noise and temperature drift influences are eliminated.
Drawings
FIG. 1 is a block diagram of the system of the present invention.
fig. 2 is an external view of a thermal flow sensor of the present invention.
Fig. 3 is a block diagram of a thermal flow sensor of the present invention.
Fig. 4 is a structural diagram of a heat flow signal amplification module according to the present invention.
Detailed Description
Referring to fig. 1, the high-resolution heat flow signal measurement system for a wide temperature region in a high magnetic environment of the invention comprises two paths of constant current source circuits, a heat flow sensor, a low temperature drift low noise amplifier module and a signal measurement circuit.
The principle of the invention is that two adjustable constant current source circuits with feedback are provided, the constant current source circuits supply power to a pair of symmetrical platinum wire temperature measuring thermal resistors of a thermal flow sensor, and the temperature difference is calculated through the voltage difference generated by two groups of platinum wire temperature measuring thermal resistors, so as to generate a differential thermal signal. The differential thermal signal is amplified through a group of low-temperature-drift low-noise amplifier modules, and finally, a sigma-delta analog-to-digital converter with high precision resolution reaching 24 bits is used for collecting and measuring.
The constant current source circuit is composed of a current output circuit, a current regulating circuit and a current collecting circuit. The current collection and the current regulation form negative feedback to control the precision of the current output by the constant current source. After adjustment, the output current of the constant current source circuit is 0.1mA, the output precision is +/-0.0001 mA, and the temperature drift coefficient is less than 20 ppm.
The heat flow sensor is a core component of the invention, the external structure is shown in figure 2, the structure is shown in figure 3, the heat flow sensor is divided into three layers, namely a bottom layer, a middle layer and a top layer, wherein the bottom layer is composed of an aluminum nitride substrate 1 with high thermal conductivity, thus realizing electrical isolation and uniform heat transfer, the middle layer is composed of a pair of completely symmetrical platinum wire temperature measuring thermal resistors 3, the platinum wire temperature measuring thermal resistors 3 are uniformly wound on a ceramic framework 2, two inner leads 4 are led out from each pair of platinum wire temperature measuring thermal resistors 3 and are led out from through holes of the substrate, the rest parts are filled with magnesium oxide powder 5 with high insulating property and high thermal conductivity, the top layer is a high-temperature glaze sealing layer 6, thereby realizing electrical isolation, the components of the heat flow sensor, the aluminum nitride substrate 1, the platinum wire temperature measuring thermal resistors 3, the inner leads 4, the magnesium oxide powder 5 and the high-temperature glaze sealing layer 6 are all made of paramagnetic materials, and are not influenced by a magnetic field in a high-magnetic field environment, the heat flow sensor adopts the platinum wire thermal resistors, the temperature measuring range can be used in-351023K, and can meet the measurement accuracy of a wide temperature measuring region, and.
The heat flow signal generated by the heat flow sensor is very weak, and the resolution of the signal is required to be +/-0.05 uV. Both weak noise and temperature drift can affect the measurement of the heat flow signal. The low-temperature drift low-noise amplifier module of the heat flow signal is an important part of the invention, and the structure is shown in figure 4. The circuit part of the low-temperature-drift low-noise amplifier module consists of a differential input circuit, a primary amplifying circuit and a secondary amplifying circuit. The amplifier forming the amplifying circuit has low temperature drift and low noise. The shell of the amplifying module is a set of constant temperature control metal magnetic shielding components. The constant temperature control metal magnetic shielding assembly is composed of a heating belt 7, heat preservation cotton 8, a temperature measuring sensor 9 and an external temperature controller, the constant temperature control assembly forms a temperature control loop, and the temperature of the control shell is always in a constant temperature state. The amplifier module operates in a constant temperature environment, which will eliminate temperature drift interference caused by ambient temperature variations and the amplifier itself. The outer surface layer of the shell adopts a permalloy shielding cover to shield external magnetic field interference.
The amplified heat flow signals are measured and collected by a sigma-delta analog-to-digital conversion chip with the resolution of 24 bits, and the signal resolution can reach one millionth.
Claims (6)
1. The utility model provides a be used for high-resolution heat flow signal measurement system under high magnetic environment wide warm area, comprises two way constant current source circuit, heat flow sensor, low temperature drift low noise amplifier module and signal measurement circuit, its characterized in that: the two paths of constant current source circuits can adjust the band feedback, the constant current source circuits supply power to a pair of symmetrical platinum wire temperature measuring thermal resistors of the heat flow sensor, the temperature difference is calculated through the voltage difference generated by the two groups of platinum wire temperature measuring thermal resistors, so that a differential thermal signal is generated, the differential thermal signal is amplified through a group of low-temperature-drift low-noise amplifier modules, and finally the differential thermal signal is acquired and measured by a sigma-delta analog-to-digital converter with the high-precision resolution reaching 24 bits; the heat flow sensor is divided into a three-layer structure, namely a bottom layer, an intermediate layer and a top layer, wherein the bottom layer is composed of a high-thermal-conductivity aluminum nitride substrate (1), the intermediate layer is composed of a pair of completely symmetrical platinum wire temperature-measuring thermal resistors (3), the platinum wire temperature-measuring thermal resistors (3) are uniformly wound on a ceramic framework (2), and two inner leads (4) are led out from each pair of platinum wire temperature-measuring thermal resistors (3) and led out from through holes of the substrate; the rest part is filled with magnesium oxide powder (5) with high insulation and high thermal conductivity; the top layer adopts a high-temperature glaze sealing layer (6) to realize electric isolation; the aluminum nitride substrate (1), the platinum wire temperature measurement thermal resistor (3), the inner lead (4), the magnesium oxide powder (5) and the high-temperature glaze sealing layer (6) are all paramagnetic materials.
2. The system of claim 1, wherein the system is used for measuring the high-resolution heat flow signal in the high magnetic environment and the wide temperature range, and comprises: the constant current source circuit consists of a current output circuit, a current regulating circuit and a current collecting circuit, and negative feedback is formed by current collection and current regulation to control the precision of the current output by the constant current source.
3. The system for measuring the high-resolution heat flow signal in the wide temperature area under the high magnetic environment according to claim 1 or 2, wherein: the output current of the constant current source circuit is 0.1mA, the output precision is +/-0.0001 mA, and the temperature drift coefficient is less than 20 ppm.
4. The system of claim 1, wherein the system is used for measuring the high-resolution heat flow signal in the high magnetic environment and the wide temperature range, and comprises: the circuit part of the low-temperature-drift low-noise amplifier module consists of a differential input circuit, a primary amplifying circuit and a secondary amplifying circuit, and a shell of the low-temperature-drift low-noise amplifier module is a constant-temperature control metal magnetic shielding assembly.
5. The system of claim 4, wherein the system is used for measuring the high-resolution heat flow signal in the high magnetic environment and the wide temperature range, and comprises: constant temperature control metal magnetism shielding subassembly comprises heating band (7), heat preservation cotton (8), temperature sensor (9) and external temperature controller, and the constant temperature control subassembly forms a control by temperature change return circuit, controls the casing temperature and is in the constant temperature state all the time.
6. The system of claim 5 for measuring high resolution heat flow signals at high magnetic environment wide temperature zone, wherein: the outer surface layer of the constant temperature control metal magnetic shielding component shell adopts a permalloy shielding cover.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810723663.4A CN108680286B (en) | 2018-07-04 | 2018-07-04 | High-resolution heat flow signal measuring system used under high-magnetic environment wide-temperature area |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810723663.4A CN108680286B (en) | 2018-07-04 | 2018-07-04 | High-resolution heat flow signal measuring system used under high-magnetic environment wide-temperature area |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108680286A CN108680286A (en) | 2018-10-19 |
| CN108680286B true CN108680286B (en) | 2019-12-10 |
Family
ID=63813140
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810723663.4A Active CN108680286B (en) | 2018-07-04 | 2018-07-04 | High-resolution heat flow signal measuring system used under high-magnetic environment wide-temperature area |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108680286B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111221358A (en) * | 2020-03-24 | 2020-06-02 | 杭州盘古自动化系统有限公司 | Method for quickly and accurately adjusting micro atmosphere flow in magnetic environment |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2393286A1 (en) * | 1976-07-15 | 1978-12-29 | Vaillant Sa | CALORIMETRIC DEVICE FOR MEASURING THE QUANTITY OF HEAT SENT BY A FLUID TO A HEAT EXCHANGER |
| DE3130499A1 (en) * | 1981-07-23 | 1983-02-10 | Abel, Konrad, Prof. Dipl.-Ing., 6834 Ketsch | Method and circuit arrangement for measuring a temperature difference |
| DE3219788C2 (en) * | 1982-05-25 | 1985-02-28 | Siemens AG, 1000 Berlin und 8000 München | Flow rate measuring device for fluids and flow rate measuring device for use as a heat meter |
| DE3751125T2 (en) * | 1986-02-04 | 1995-08-10 | Sharp Kk | Moisture measuring circuit. |
| CN100535612C (en) * | 2005-05-26 | 2009-09-02 | 郭豫生 | Heat conduction sensor and measuring method thereof |
| CN201007805Y (en) * | 2007-01-08 | 2008-01-16 | 深圳市国冶星光电子有限公司 | Digital type adjustable constant-current constant voltage source |
| CN201926947U (en) * | 2010-12-29 | 2011-08-10 | 上海亨通光电科技有限公司 | Duty ratio adjustable current source based on singlechip control |
| CN103308214B (en) * | 2013-05-13 | 2016-01-13 | 华北电力大学 | A kind of hot-fluid real-time detection apparatus and hot-fluid real-time detection method thereof |
| CN104964759A (en) * | 2015-07-21 | 2015-10-07 | 华军 | Quick-response bimetal thermometer temperature bulb structure |
| CN105554940A (en) * | 2015-12-25 | 2016-05-04 | 北京经纬恒润科技有限公司 | Adaptive adjustment circuit for automotive load current |
-
2018
- 2018-07-04 CN CN201810723663.4A patent/CN108680286B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN108680286A (en) | 2018-10-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Qu et al. | Johnson noise thermometry | |
| Scott et al. | New thermocouple-based microwave/millimeter-wave power sensor MMIC techniques in GaAs | |
| CN108562381B (en) | Thin film sensor for measuring heat flow in high-temperature environment and manufacturing method thereof | |
| CN209432889U (en) | A kind of bimag Low Drift Temperature Hall current sensor | |
| CN109444513A (en) | A kind of bimag Low Drift Temperature Hall current sensor | |
| CN108680286B (en) | High-resolution heat flow signal measuring system used under high-magnetic environment wide-temperature area | |
| Wilkins | Theoretical analysis of the AC/DC transfer difference of the NPL multijunction thermal convertor over the frequency range DC to 100 kHz | |
| Fleischmann et al. | Noise thermometry for ultralow temperatures | |
| Boyd et al. | Integrated SQUID/sensor metallic magnetic microcalorimeter for gamma-ray spectroscopy | |
| Brixy | Temperature measurement in nuclear reactors by noise thermometry | |
| Kettler et al. | Differential ac method of thermopower measurement | |
| CN208537609U (en) | A kind of current measuring device that high-precision is easy to install | |
| Kirste et al. | A calculable and correlation-based magnetic field fluctuation thermometer | |
| CN104122469A (en) | Method for increasing measured seebeck coefficient accuracy of thermoelectric material | |
| CN108918939A (en) | A kind of current measuring device that high-precision is easy to install | |
| Fujiki | New thin-film multijunction thermal converter design for improved high-frequency performance | |
| Kubiczek et al. | A novel temperature sensor for a calorimetric thermal converter | |
| Katzmann et al. | Thin-film AC-DC converter with thermoresistive sensing | |
| Netsch et al. | Novel, non‐contact noise thermometer for Milli‐kelvin temperatures | |
| Xia et al. | Design of an optimized electrothermal filter for a temperature-to-frequency converter | |
| Nowak et al. | Test stand for temperature characteristics of ultra-precise resistors | |
| Amagai et al. | Improvements in the low-frequency characteristic and sensitivity of a thin-film multijunction thermal converter in vacuum | |
| Fujiki et al. | Fabrication of thin film multijunction thermal converters with improved long-term stability | |
| Immonen | A heat flux sensor test setup | |
| Ding et al. | Design, Fabrication, and Characterization of a Pt/Au Thin-Film Thermocouple Array |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |