A universal and low-cost temperature thermometer is realized via a special circuit,integrated circuit chip with microprocessor and analog to digital converter,and digital bus interface.Various thermocouples and resist...A universal and low-cost temperature thermometer is realized via a special circuit,integrated circuit chip with microprocessor and analog to digital converter,and digital bus interface.Various thermocouples and resistance temperature detectors used for temperature sensing may be connected to same thermometer.A special signal condition circuitry is designed and a matching algorithm is proposed.A novel calibration method named disassembled calibration is proposed in order to enhance efficiency and flexibility for the whole system.Additionally,it presents a combination method of low order polynomial fitting and piecewise linearity for the nonlinearity calibration of the thermocouple and the resistance temperature detector.A cold junction compensation based on digital way is described.And the matching algorithm and calibration method may eliminate errors stemming from excitation voltage source and reference voltage source,and can weaken quantization error of analog to digital converter and drift of components,too.Furthermore,the 400 times oversampling is completed by sequential and equal interval sampling to upgrade accuracy of analog to digital converter from original 12 to 15 bits and to raise signal-to-noise ratio.Finally,during a long time monitoring,experiment results show that errors at each static point are less than±0.2°C for the thermocouple system and less than±0.1°C for the resistance temperature detector system.展开更多
The soft X-ray spectroscopy, laser Thomson scattering and electron cyclotron emission ( ECE ) are usually adopted for electron temperature measurement in fusion research of magnetic confinement. The particular soft ...The soft X-ray spectroscopy, laser Thomson scattering and electron cyclotron emission ( ECE ) are usually adopted for electron temperature measurement in fusion research of magnetic confinement. The particular soft X-ray spectroscopy has the very good spatial-temporal resolution and smaller measuring error than laser Thomson scattering, a close spatial-temporal resolution to ECE, absolute measurement ability, and smaller influence by suprathermal and runaway electrons than ECE.展开更多
γ-ray and x-ray detectors made by Cd1-xZnxTe alloy can gain high energy resolution and detect efficiency at room temperature due to its high atomic number,large energy gap and high density,which were well-developed r...γ-ray and x-ray detectors made by Cd1-xZnxTe alloy can gain high energy resolution and detect efficiency at room temperature due to its high atomic number,large energy gap and high density,which were well-developed recently.By well controlled of Cadmium partial pressure and compensatory doping technique,Ф90 mm Cd1-xZnxTe alloy obtained successfully(ρ≥1011Ω·cm)by an improved-Bridgman method.3 mm×3 mm×3 mm CZT detector was made at Kunming Institute of Physics,which has energy resolution of 3.52%(FWHM)at room temperature when detect 59.54 KeV Am241γ-ray source.展开更多
The spontaneous combustion event in coal stockpiles is inevitable when appropriate environmental conditions are available. The objective of a computerized measurement system is to measure temperature changes existing ...The spontaneous combustion event in coal stockpiles is inevitable when appropriate environmental conditions are available. The objective of a computerized measurement system is to measure temperature changes existing in a coal stockpile. In order to achieve this intention, the electrical signal conversion of temperatures sensed by 20 temperature sensors placed in certain points inside the coal stockpile, the transfer of these electrical signals into computer media by using analogue-digital conversion unit after applying necessary filterization and upgrading processes and the record of these information into a database in particular time intervals are provided. Afterwards, the diagrams of these time-temperature data are plotted. With the help of these graphs, the competent company will be able to examine the behavior of coal stockpiles in terms of spontaneous combustion and take necessary precautions against self-combustion beforehand.展开更多
基金the Beijing Municipal Education Commission Science Technology Fund(No.KM201411232015)the Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges Under Beijing Municipality(No.IDHT20130519)the National Natural Science Foundation of China(No.61272375)
文摘A universal and low-cost temperature thermometer is realized via a special circuit,integrated circuit chip with microprocessor and analog to digital converter,and digital bus interface.Various thermocouples and resistance temperature detectors used for temperature sensing may be connected to same thermometer.A special signal condition circuitry is designed and a matching algorithm is proposed.A novel calibration method named disassembled calibration is proposed in order to enhance efficiency and flexibility for the whole system.Additionally,it presents a combination method of low order polynomial fitting and piecewise linearity for the nonlinearity calibration of the thermocouple and the resistance temperature detector.A cold junction compensation based on digital way is described.And the matching algorithm and calibration method may eliminate errors stemming from excitation voltage source and reference voltage source,and can weaken quantization error of analog to digital converter and drift of components,too.Furthermore,the 400 times oversampling is completed by sequential and equal interval sampling to upgrade accuracy of analog to digital converter from original 12 to 15 bits and to raise signal-to-noise ratio.Finally,during a long time monitoring,experiment results show that errors at each static point are less than±0.2°C for the thermocouple system and less than±0.1°C for the resistance temperature detector system.
文摘The soft X-ray spectroscopy, laser Thomson scattering and electron cyclotron emission ( ECE ) are usually adopted for electron temperature measurement in fusion research of magnetic confinement. The particular soft X-ray spectroscopy has the very good spatial-temporal resolution and smaller measuring error than laser Thomson scattering, a close spatial-temporal resolution to ECE, absolute measurement ability, and smaller influence by suprathermal and runaway electrons than ECE.
文摘γ-ray and x-ray detectors made by Cd1-xZnxTe alloy can gain high energy resolution and detect efficiency at room temperature due to its high atomic number,large energy gap and high density,which were well-developed recently.By well controlled of Cadmium partial pressure and compensatory doping technique,Ф90 mm Cd1-xZnxTe alloy obtained successfully(ρ≥1011Ω·cm)by an improved-Bridgman method.3 mm×3 mm×3 mm CZT detector was made at Kunming Institute of Physics,which has energy resolution of 3.52%(FWHM)at room temperature when detect 59.54 KeV Am241γ-ray source.
文摘The spontaneous combustion event in coal stockpiles is inevitable when appropriate environmental conditions are available. The objective of a computerized measurement system is to measure temperature changes existing in a coal stockpile. In order to achieve this intention, the electrical signal conversion of temperatures sensed by 20 temperature sensors placed in certain points inside the coal stockpile, the transfer of these electrical signals into computer media by using analogue-digital conversion unit after applying necessary filterization and upgrading processes and the record of these information into a database in particular time intervals are provided. Afterwards, the diagrams of these time-temperature data are plotted. With the help of these graphs, the competent company will be able to examine the behavior of coal stockpiles in terms of spontaneous combustion and take necessary precautions against self-combustion beforehand.