We propose a low-cost compact microfluidic temperature sensor by virtue of the temperature-dependent permittivity of liquid.The sensor is composed of a coplanar waveguide(CPW)transmission line loaded with three resona...We propose a low-cost compact microfluidic temperature sensor by virtue of the temperature-dependent permittivity of liquid.The sensor is composed of a coplanar waveguide(CPW)transmission line loaded with three resonators and a microfluidic plate with three channels.The resonant frequency of each resonator relies on the temperature-dependent dielectric property of liquid in corresponding channel,which therefore can be used to extract the temperature.The proposed sensor features a compact size and low cost since it requires only micro fluid volume instead of additional electronic components to produce significant frequency shift with changing temperature.Moreover,it exhibits decent accuracy and stability in a temperature sensing range from 30℃ to 95℃.A theoretical analysis of the sensor is provided,followed by the detailed characterization method,and a prototype is designed,manufactured,and measured to verify the theoretical analysis.展开更多
A highly sensitive optical fiber temperature sensor based on a section of liquid-filled silica capillary tube(SCT)between single mode fibers is proposed. Two micro-holes are drilled on two sides of SCT directly by usi...A highly sensitive optical fiber temperature sensor based on a section of liquid-filled silica capillary tube(SCT)between single mode fibers is proposed. Two micro-holes are drilled on two sides of SCT directly by using femtosecond laser micromachining, and liquid polymer is filled into the SCT through the micro-holes without any air bubbles and then sealed by using ultra-violet(UV) cure adhesive. The sidewall of the SCT forms a Fabry–Perot resonator, and loss peaks are achieved in the transmission spectrum of the SCT at the resonant wavelength. The resonance condition can be influenced by the refractive index variation of the liquid polymer filled in SCT, which is sensitive to temperature due to its high thermooptical coefficient(-2.98 × 10^-4℃^-1). The experimental result shows that the temperature sensitivity of the proposed fiber structure reaches 5.09 nm/℃ with a perfect linearity of 99.8%. In addition, it exhibits good repeatability and reliability in temperature sensing application.展开更多
In this paper, a new wireless measuring method for colorless liquid level measurement was presented, based on latest CLC100 liquid level sensor and Powercast wireless sensor development kit. The wireless system is div...In this paper, a new wireless measuring method for colorless liquid level measurement was presented, based on latest CLC100 liquid level sensor and Powercast wireless sensor development kit. The wireless system is divided into two parts, level measurement and data transmission part as well as data receiving and display part. First part included the capacitive liquid level sensor CLC100 and the wireless senor board. CLC100 sensor was used for liquid level measurement. Wireless sensor kit from Powercast Corporation included one wireless sensor board, which was used for signal transmission. A built-in PIC microcontroller was embedded in the transmission module, for the purpose of processing and data transmitting. Due to CLC100 sensor’s output voltage exceeding the sensor board’s input limitation, a voltage convertor was designed to connect the sensor and the wireless sensor board. The final results were voltages corresponding to the liquid level, and were processed by an independent PIC development board, and then sent to PC’s hyper terminal via serial-port by this PIC microcontroller. Experiments showed that this wireless sensor node prototype worked well.展开更多
An unexpected frequency response for a piezoelectric quartz crystal (PQC) sensor to liquid density and viscosity was reported. For a PQC oscillating in a liquid phase, the frequency shifts (?f ) show a wave-shape re...An unexpected frequency response for a piezoelectric quartz crystal (PQC) sensor to liquid density and viscosity was reported. For a PQC oscillating in a liquid phase, the frequency shifts (?f ) show a wave-shape response to liquid density (ρ) and viscosity (η) in fine structure, if the longitudinal wave effect was not eliminated. This result is different from the well-known linear relationship between of ?f and (ρη)1/2. An oscillating frequency-temperature curve of the sensor was observed and explained.展开更多
A linear acceleration sensor,which is inspired by the human balance organ,is designed and prepared. It uses a liquid mass-block and a symmetrical-electrodes metal-core polyvinylidene fluoride fiber(SMPF)as the sensor ...A linear acceleration sensor,which is inspired by the human balance organ,is designed and prepared. It uses a liquid mass-block and a symmetrical-electrodes metal-core polyvinylidene fluoride fiber(SMPF)as the sensor element. The output signal of the sensor has an exponential relationship with the excitation amplitude of the impacting vibration. It is capable of detecting the amplitude and the correct frequency for sinusoidal excitations using an exponential correlation. The experiments indicate that both the output signal of the sensor and the resonance frequency increase substantially with increasing diameter of the metal core. The first-order resonance frequencies of the sensors with 40,60,and 80 μm diameter metal wires are below 10 Hz,which is near the range of human body motion frequencies.展开更多
An electrochemical sensor incorporating a signal enhancement for the determination of lead （II） ions （Pb2＋） was designed on the basis of the thrombin-binding aptamer （TBA） as a molecular recog- nition element a...An electrochemical sensor incorporating a signal enhancement for the determination of lead （II） ions （Pb2＋） was designed on the basis of the thrombin-binding aptamer （TBA） as a molecular recog- nition element and ionic liquid supported cerium oxide （CeO2） nanoparticles-carbon nanotubes compo- site modification. The composite comprises nanoparticles CeO2, multi-waU carbon nanotubes （MWNTs） and hydrophobic room temperature ionic liquid （RTIL） 1-ethyl-3-methylimidazolium tetrafluoroborate （EMIMBF4）. The electrochemical sensors were fabricated by immersing the CeOa-MWNTs-EMIMBF4 modified glassy carbon electrode （GCE） into the solution of TBA probe. In the presence of Pb2＋, the TBA probe could form stable G-quartet structure by the specific binding interactions between Pb2＋ and TBA. The TBA-bound Pb2＋ can be electrochemically reduced, which provides a readout signal for quantitative detection of Pb2＋. The reduction peak current is linearly related to the concentration of Pb2＋ from 1.0 ＊ 10-8 M to 1.0 ＊ 105 M with a detection limit of 5 ＊ 109 M. This work demonstrates that the CeOz-MWNTs-EMIMBF4 nanocomposite modified GCE provides a promising platform for immobi- lizing the TBA probe and enhancing the sensitivity of the DNA-based sensors.展开更多
Photonic crystal fiber (PCF) is employed as a refractive index sensor (RIS) for solving a lot of problems in biological, physicochemical, medical, engineering fields and many environmental challenges, where it is used...Photonic crystal fiber (PCF) is employed as a refractive index sensor (RIS) for solving a lot of problems in biological, physicochemical, medical, engineering fields and many environmental challenges, where it is used in many industries of food, medicines, chemical materials and material diagnosis. The kind of the PCFs was HC-1550 with three wavelengths of laser source were used;638 nm, 850 nm, and 1550 nm that are useful for recording the intended transmitted signal intensity. Therefore, the measured RI was in the range (1.469 - 1.455 RIU) at the temperature range (36 - 70)°C for the EBBA and it was (1.621 - 1.612 RIU) at the temperature range (22 - 42)°C for the MBBA. The results showed that the highest RI sensitivity was 96.335 dBm/RIU for the HC-1550 infiltrated with MBBA using the laser of wavelength 638 nm, Also, the highest temperature sensitivity was 0.2505 dBm/°C for empty HC-1550 using the laser of wavelength 1550 nm.展开更多
When I read the paper of“Crystal-Confined Freestanding Ionic Liquids for Reconfigurable and Repairable Electronics”that was published on Nature Communications(Nat.Commun.2019,10,547),I felt excited as it led to a ne...When I read the paper of“Crystal-Confined Freestanding Ionic Liquids for Reconfigurable and Repairable Electronics”that was published on Nature Communications(Nat.Commun.2019,10,547),I felt excited as it led to a new application of ionic liquids in addition to the enormous studies on chemical synthesis,catalysis,gas adsorption,processing biomass,and electrochemistry.This paper intended to mimic the liquid robot which was a classic character in the famous movie of Terminator 2:Judgment Day.The authors successfully exploited an approach to overcome the leakage problem of ionic liquids in the absence of encapsulation layers.It seems that ionic liquids would be one of the promising materials for green electronics with less production of electronic waste.In these regards,I would be delighted to write a highlight for this innovative work and hopefully it may raise more interests in the areas of ionic liquids.展开更多
The study of liquid film characteristics in multiphase flow is a very important research topic, however,the characteristics of the liquid film around Taylor bubble structure in gas, oil and water three-phase flow are ...The study of liquid film characteristics in multiphase flow is a very important research topic, however,the characteristics of the liquid film around Taylor bubble structure in gas, oil and water three-phase flow are not clear. In the present study, a novel liquid film sensor is applied to measure the distributed signals of the liquid film in three-phase flow. Based on the liquid film signals, the liquid film characteristics including the structural characteristics and the nonlinear dynamics characteristics in three-phase flows are investigated for the first time. The structural characteristics including the proportion, the appearance frequency and the thickness of the liquid film are obtained and the influences of the liquid and gas superficial velocities and the oil content on them are investigated. To investigate the nonlinear dynamics characteristics of the liquid film with the changing flow conditions, the entropy analysis is introduced to successfully uncover and quantify the dynamic complexity of the liquid film behavior.展开更多
The frequency responses of a langasite crystal microbalance （LCM） in liquid phase were investigated. It was shown that the LCM possessed much stronger oscillating ability in liquid phase than that of the commonly us...The frequency responses of a langasite crystal microbalance （LCM） in liquid phase were investigated. It was shown that the LCM possessed much stronger oscillating ability in liquid phase than that of the commonly used quartz crystal microbalance （QCM）. The frequency shifts of the LCM to the changes in mass loading, as well as viscosity and density of the liquid were measured. The LCM was applied to monitor the adsorption process of an ionic liquid film to ethanol vapor.展开更多
This paper investigates the selective liquid response for Morpho didius butterfly wing scales and propose an optical model to explain the effect of different components on the liquid response. It is found out that the...This paper investigates the selective liquid response for Morpho didius butterfly wing scales and propose an optical model to explain the effect of different components on the liquid response. It is found out that the reason of the selective response is that the liquid media forms nanometre-thick films between ridge-lamellae nanostructures and changes the constructive interference wavelength. There is linear relation between the structural color of ridge-lamellae structure and index of liquid background media. The reason of vapor＇s responses is that the nanometre-thick liquid fi lms on ridge-lamellae nanostructures change the constructive interference wavelength. These liquid films are formed due to vapor adsorption. Therefore,the selective linear liquid response can be applied to design nano-engineered photonic liquid and vapor sensors.展开更多
Utilizing the technology of Ultrasonic wave,relevant test arithmetic and the PC to carry on monitoring,controlling and cen-tralized management of the liquid-level in the liquid container. It can prevent from keeping i...Utilizing the technology of Ultrasonic wave,relevant test arithmetic and the PC to carry on monitoring,controlling and cen-tralized management of the liquid-level in the liquid container. It can prevent from keeping in touch with the examined liquid,not only has increased the continuous working time of the system greatly,simplifying maintenance of the sensor conveniently,can also realize overhauling in producing and boost the productivity and management level. The working principle,hardware structure of the instrument and the design method are presented,and the selection of sensor and MCU is discussed in detail in this paper. MCU are used to control the emission and receiving. Then the liquid-level are calculated,which makes the design more intelligent.展开更多
Liquid lead-lithium (Pb-16Li) is of primary interest as one of the candidate materials for tritium breeder, neutron multiplier and coolant fluid in liquid metal blanket concepts relevant to fusion power plants. For an...Liquid lead-lithium (Pb-16Li) is of primary interest as one of the candidate materials for tritium breeder, neutron multiplier and coolant fluid in liquid metal blanket concepts relevant to fusion power plants. For an effective and reliable operation of such high temperature liquid metal systems, monitoring and control of critical process parameters is essential. However, limited operational experience coupled with high temperature operating conditions and corrosive nature of Pb-16Li severely limited application of commercially available diagnostic tools. This paper illustrates indigenous calibration test facility designs and experimental methods used to develop non-contact configuration level diagnostics using pulse radar level sensor, wetted configuration pressure diagnostics using diaphragm seal type pressure sensor and bulk temperature diagnostics with temperature profiling for high temperature, high pressure liquid Pb and Pb-16Li applications. Calibration check of these sensors was performed using analytical methods, at temperature between 380°C - 400°C and pressure upto 1 MPa (g). Reliability and performance validation were achieved through long duration testing of sensors in liquid Pb and liquid Pb-16Li environment for over 1000 hour. Estimated deviation for radar level sensor lies within [−3.36 mm, +13.64 mm] and the estimated error for pressure sensor lies within 1.1% of calibrated span over the entire test duration. Results obtained and critical observations from these tests are presented in this paper.展开更多
In this paper, the dependences of the frequeucy-temperature coefficient (df/dt) of an electrode-sepa-rated piezolectric sensor(ESPS) on desity, viscosity, permittivity and conductivity of the solution to be tested wer...In this paper, the dependences of the frequeucy-temperature coefficient (df/dt) of an electrode-sepa-rated piezolectric sensor(ESPS) on desity, viscosity, permittivity and conductivity of the solution to be tested were investigated’ A comparison of the frequency -temperature coefficient between the ESPS and a conwentioal piezoelectric quartz crystal was made, In a nou-electrolyte liquid, the df/dt)walwe of the ESPS increases with the increase of viscosity, density and permittivity of the liquid There is df/dt>0 in low or high conductivity solutions, but df/dt>0 in middle conductivity solution.And two zoues where df/dt is approximately equal to zero are observed in electrolyte展开更多
基金Project supported by the Natural Science Foundation of Zhejiang Province,China(Grant No.LQ19F010007)the National Natural Science Foundation of China(Grants Nos.61901146 and 61874038)the Smart City Collaborative Innovation Center of Zhejiang Province,China
文摘We propose a low-cost compact microfluidic temperature sensor by virtue of the temperature-dependent permittivity of liquid.The sensor is composed of a coplanar waveguide(CPW)transmission line loaded with three resonators and a microfluidic plate with three channels.The resonant frequency of each resonator relies on the temperature-dependent dielectric property of liquid in corresponding channel,which therefore can be used to extract the temperature.The proposed sensor features a compact size and low cost since it requires only micro fluid volume instead of additional electronic components to produce significant frequency shift with changing temperature.Moreover,it exhibits decent accuracy and stability in a temperature sensing range from 30℃ to 95℃.A theoretical analysis of the sensor is provided,followed by the detailed characterization method,and a prototype is designed,manufactured,and measured to verify the theoretical analysis.
基金Project supported by the Scientific Research Project of Institutions of Higher Learning in Inner Mongolia Autonomous Region,China(Grant No.NJZY19214)
文摘A highly sensitive optical fiber temperature sensor based on a section of liquid-filled silica capillary tube(SCT)between single mode fibers is proposed. Two micro-holes are drilled on two sides of SCT directly by using femtosecond laser micromachining, and liquid polymer is filled into the SCT through the micro-holes without any air bubbles and then sealed by using ultra-violet(UV) cure adhesive. The sidewall of the SCT forms a Fabry–Perot resonator, and loss peaks are achieved in the transmission spectrum of the SCT at the resonant wavelength. The resonance condition can be influenced by the refractive index variation of the liquid polymer filled in SCT, which is sensitive to temperature due to its high thermooptical coefficient(-2.98 × 10^-4℃^-1). The experimental result shows that the temperature sensitivity of the proposed fiber structure reaches 5.09 nm/℃ with a perfect linearity of 99.8%. In addition, it exhibits good repeatability and reliability in temperature sensing application.
文摘In this paper, a new wireless measuring method for colorless liquid level measurement was presented, based on latest CLC100 liquid level sensor and Powercast wireless sensor development kit. The wireless system is divided into two parts, level measurement and data transmission part as well as data receiving and display part. First part included the capacitive liquid level sensor CLC100 and the wireless senor board. CLC100 sensor was used for liquid level measurement. Wireless sensor kit from Powercast Corporation included one wireless sensor board, which was used for signal transmission. A built-in PIC microcontroller was embedded in the transmission module, for the purpose of processing and data transmitting. Due to CLC100 sensor’s output voltage exceeding the sensor board’s input limitation, a voltage convertor was designed to connect the sensor and the wireless sensor board. The final results were voltages corresponding to the liquid level, and were processed by an independent PIC development board, and then sent to PC’s hyper terminal via serial-port by this PIC microcontroller. Experiments showed that this wireless sensor node prototype worked well.
基金supported by the National Natural Science Foundation of China(No.20275021)
文摘An unexpected frequency response for a piezoelectric quartz crystal (PQC) sensor to liquid density and viscosity was reported. For a PQC oscillating in a liquid phase, the frequency shifts (?f ) show a wave-shape response to liquid density (ρ) and viscosity (η) in fine structure, if the longitudinal wave effect was not eliminated. This result is different from the well-known linear relationship between of ?f and (ρη)1/2. An oscillating frequency-temperature curve of the sensor was observed and explained.
基金supported by the National Natural Science Foundation of China(Nos. 51775483 and 51275447)the Research Innovation Program for College Graduates of Jiangsu Province(No.SJLX_0589)
文摘A linear acceleration sensor,which is inspired by the human balance organ,is designed and prepared. It uses a liquid mass-block and a symmetrical-electrodes metal-core polyvinylidene fluoride fiber(SMPF)as the sensor element. The output signal of the sensor has an exponential relationship with the excitation amplitude of the impacting vibration. It is capable of detecting the amplitude and the correct frequency for sinusoidal excitations using an exponential correlation. The experiments indicate that both the output signal of the sensor and the resonance frequency increase substantially with increasing diameter of the metal core. The first-order resonance frequencies of the sensors with 40,60,and 80 μm diameter metal wires are below 10 Hz,which is near the range of human body motion frequencies.
基金supports from the National Science Foundations of China (Nos. 20875076 and 21005061)the Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 20096101120011)+2 种基金the Natural Science Basic Research Plan in Shaanxi Province of China (No.2010JQ2013)the Education Department of Shaanxi Province,China (No. 09JK759)the NWU Graduate Innovation and Creativity Funds (No. 09YSY04)
文摘An electrochemical sensor incorporating a signal enhancement for the determination of lead （II） ions （Pb2＋） was designed on the basis of the thrombin-binding aptamer （TBA） as a molecular recog- nition element and ionic liquid supported cerium oxide （CeO2） nanoparticles-carbon nanotubes compo- site modification. The composite comprises nanoparticles CeO2, multi-waU carbon nanotubes （MWNTs） and hydrophobic room temperature ionic liquid （RTIL） 1-ethyl-3-methylimidazolium tetrafluoroborate （EMIMBF4）. The electrochemical sensors were fabricated by immersing the CeOa-MWNTs-EMIMBF4 modified glassy carbon electrode （GCE） into the solution of TBA probe. In the presence of Pb2＋, the TBA probe could form stable G-quartet structure by the specific binding interactions between Pb2＋ and TBA. The TBA-bound Pb2＋ can be electrochemically reduced, which provides a readout signal for quantitative detection of Pb2＋. The reduction peak current is linearly related to the concentration of Pb2＋ from 1.0 ＊ 10-8 M to 1.0 ＊ 105 M with a detection limit of 5 ＊ 109 M. This work demonstrates that the CeOz-MWNTs-EMIMBF4 nanocomposite modified GCE provides a promising platform for immobi- lizing the TBA probe and enhancing the sensitivity of the DNA-based sensors.
文摘Photonic crystal fiber (PCF) is employed as a refractive index sensor (RIS) for solving a lot of problems in biological, physicochemical, medical, engineering fields and many environmental challenges, where it is used in many industries of food, medicines, chemical materials and material diagnosis. The kind of the PCFs was HC-1550 with three wavelengths of laser source were used;638 nm, 850 nm, and 1550 nm that are useful for recording the intended transmitted signal intensity. Therefore, the measured RI was in the range (1.469 - 1.455 RIU) at the temperature range (36 - 70)°C for the EBBA and it was (1.621 - 1.612 RIU) at the temperature range (22 - 42)°C for the MBBA. The results showed that the highest RI sensitivity was 96.335 dBm/RIU for the HC-1550 infiltrated with MBBA using the laser of wavelength 638 nm, Also, the highest temperature sensitivity was 0.2505 dBm/°C for empty HC-1550 using the laser of wavelength 1550 nm.
文摘When I read the paper of“Crystal-Confined Freestanding Ionic Liquids for Reconfigurable and Repairable Electronics”that was published on Nature Communications(Nat.Commun.2019,10,547),I felt excited as it led to a new application of ionic liquids in addition to the enormous studies on chemical synthesis,catalysis,gas adsorption,processing biomass,and electrochemistry.This paper intended to mimic the liquid robot which was a classic character in the famous movie of Terminator 2:Judgment Day.The authors successfully exploited an approach to overcome the leakage problem of ionic liquids in the absence of encapsulation layers.It seems that ionic liquids would be one of the promising materials for green electronics with less production of electronic waste.In these regards,I would be delighted to write a highlight for this innovative work and hopefully it may raise more interests in the areas of ionic liquids.
基金supported by the National Natural Science Foundation of China (42074142, 51527805, 41974139)China Postdoctoral Science Foundation (2020M680969, 2021T140099)the Fundamental Research Funds for the Central Universities (N2104013)。
文摘The study of liquid film characteristics in multiphase flow is a very important research topic, however,the characteristics of the liquid film around Taylor bubble structure in gas, oil and water three-phase flow are not clear. In the present study, a novel liquid film sensor is applied to measure the distributed signals of the liquid film in three-phase flow. Based on the liquid film signals, the liquid film characteristics including the structural characteristics and the nonlinear dynamics characteristics in three-phase flows are investigated for the first time. The structural characteristics including the proportion, the appearance frequency and the thickness of the liquid film are obtained and the influences of the liquid and gas superficial velocities and the oil content on them are investigated. To investigate the nonlinear dynamics characteristics of the liquid film with the changing flow conditions, the entropy analysis is introduced to successfully uncover and quantify the dynamic complexity of the liquid film behavior.
基金supported by the National Natural Science Foundation of China(No.20275021)the Open Foundation of the State Key Laboratory of Chemo/Biosensing and Chemometrics,Hunan University.
文摘The frequency responses of a langasite crystal microbalance （LCM） in liquid phase were investigated. It was shown that the LCM possessed much stronger oscillating ability in liquid phase than that of the commonly used quartz crystal microbalance （QCM）. The frequency shifts of the LCM to the changes in mass loading, as well as viscosity and density of the liquid were measured. The LCM was applied to monitor the adsorption process of an ionic liquid film to ethanol vapor.
基金Supported by the National Natural Science Foundation of China(51305129)the Natural Science Foundation of Hubei Province(Q20151411)
文摘This paper investigates the selective liquid response for Morpho didius butterfly wing scales and propose an optical model to explain the effect of different components on the liquid response. It is found out that the reason of the selective response is that the liquid media forms nanometre-thick films between ridge-lamellae nanostructures and changes the constructive interference wavelength. There is linear relation between the structural color of ridge-lamellae structure and index of liquid background media. The reason of vapor＇s responses is that the nanometre-thick liquid fi lms on ridge-lamellae nanostructures change the constructive interference wavelength. These liquid films are formed due to vapor adsorption. Therefore,the selective linear liquid response can be applied to design nano-engineered photonic liquid and vapor sensors.
文摘Utilizing the technology of Ultrasonic wave,relevant test arithmetic and the PC to carry on monitoring,controlling and cen-tralized management of the liquid-level in the liquid container. It can prevent from keeping in touch with the examined liquid,not only has increased the continuous working time of the system greatly,simplifying maintenance of the sensor conveniently,can also realize overhauling in producing and boost the productivity and management level. The working principle,hardware structure of the instrument and the design method are presented,and the selection of sensor and MCU is discussed in detail in this paper. MCU are used to control the emission and receiving. Then the liquid-level are calculated,which makes the design more intelligent.
文摘Liquid lead-lithium (Pb-16Li) is of primary interest as one of the candidate materials for tritium breeder, neutron multiplier and coolant fluid in liquid metal blanket concepts relevant to fusion power plants. For an effective and reliable operation of such high temperature liquid metal systems, monitoring and control of critical process parameters is essential. However, limited operational experience coupled with high temperature operating conditions and corrosive nature of Pb-16Li severely limited application of commercially available diagnostic tools. This paper illustrates indigenous calibration test facility designs and experimental methods used to develop non-contact configuration level diagnostics using pulse radar level sensor, wetted configuration pressure diagnostics using diaphragm seal type pressure sensor and bulk temperature diagnostics with temperature profiling for high temperature, high pressure liquid Pb and Pb-16Li applications. Calibration check of these sensors was performed using analytical methods, at temperature between 380°C - 400°C and pressure upto 1 MPa (g). Reliability and performance validation were achieved through long duration testing of sensors in liquid Pb and liquid Pb-16Li environment for over 1000 hour. Estimated deviation for radar level sensor lies within [−3.36 mm, +13.64 mm] and the estimated error for pressure sensor lies within 1.1% of calibrated span over the entire test duration. Results obtained and critical observations from these tests are presented in this paper.
文摘In this paper, the dependences of the frequeucy-temperature coefficient (df/dt) of an electrode-sepa-rated piezolectric sensor(ESPS) on desity, viscosity, permittivity and conductivity of the solution to be tested were investigated’ A comparison of the frequency -temperature coefficient between the ESPS and a conwentioal piezoelectric quartz crystal was made, In a nou-electrolyte liquid, the df/dt)walwe of the ESPS increases with the increase of viscosity, density and permittivity of the liquid There is df/dt>0 in low or high conductivity solutions, but df/dt>0 in middle conductivity solution.And two zoues where df/dt is approximately equal to zero are observed in electrolyte
