859results about "Material thermal coefficient of expansion" patented technology

The invention discloses a device and a method for high-accuracy measurement of expansion coefficients of a metal wire. The method uses a PZT oscillating mirror system to perform frequency modulation on incident light at different times, can not only modulate parameter information to be measured to a phase difference, but also modulate the parameter information to be measured to in a frequency difference for the convenience of later signal treatments; and the device consists of an interference system, a high-speed PZT oscillating mirror system, a heating system and a signal processing system. Comparing the method with other measuring methods, a multi-beam laser heterodyne measuring method for measuring the expansion coefficients of the metal wire has the advantages of high space and time resolutions, high measurement accuracy, high linearity, quick dynamic response, large measuring range and the like, and simultaneously the method has the advantages of simple structure for an experimental apparatus, low power consumption, convenient operation, high repeatability, small experimental result error, high accuracy and the like. Because experimental phenomena are obvious and experimental data is reliable, the method and the device can be widely applied in the fields of engineering designs and the like, and have very high practical values in the field of laser ultra-precision measurements.

An analyzer characterized by comprising a chip and a detector, wherein the chip is an organic polymer member having a fine capillary through which a fluid sample or a fluid sample and a fluid reagent flow and can perform a chemical reaction on the sample in the capillary without using a separate weighing means, and the detector is a photothermal conversion detector for measuring a physical quantity change such as a refractive index change caused by a partial temperature change of the sample and the reagent by applying an excitation light to a substance to be measured produced by the chemical reaction, thereby providing a small analyzer excellent in chip waste-disposal, capable of analyzing inexpensively, simply and in a short time and being suitable for a POC analysis.

Disclosed are a testing apparatus for and a method of measuring thermal stresses of concrete structures. Overcoming the limitations that conventional analytical access techniques have, the apparatus opens a new way to conveniently measure the thermal stress attributable to the heat of hydration generated in concrete structures indoors. Using a material different in coefficient of thermal expansion from concrete, the apparatus can directly measure the change in thermal stress of the concrete which is subjected to internal and/or external confinement. By using various materials, the thermal stress which varies depending on the confinement extent can be inferred. Additionally, an accurate prediction of the thermal stresses generated actually in concrete can be obtained, reflecting unclear physical properties of early-age concrete.

Instruments and methods for measuring a property of a shape memory alloy are provided. The instrument includes a base plate, a non-contact movable mass, a force gauge, an actuator, a biasing spring, a heater for heating the shape memory alloy, and a non-contact displacement detector. The biasing spring and the shape memory alloy are disposed whereby a force applied thereby is applied substantially through a center of stiffness of the movable mass. The displacement detector measures a displacement of the movable mass in a colinear direction with a direction of movement of the movable mass and with a direction of the force applied by the biasing spring and the shape memory alloy. The linear motion stage comprises a housing and at least one guide bar, and wherein a calculated axial expansion of the guide bar is substantially equal to a calculated axial expansion of the base plate.

An AFM based technique has been demonstrated for performing highly localized IR spectroscopy on a sample surface. Such a technique implemented in a commercially viable analytical instrument would be extremely useful. Various aspects of the experimental set-up have to be changed to create a commercial version. The invention addresses many of these issues thereby producing a version of the analytical technique that cab be made generally available to the scientific community.

In a thermomechanical measuring device and a thermogravimetry device, partition walls are provided in two sections such that two kinds of atmospheric gasses, which have passed a sample chamber and a detector chamber, respectively, do not flow back, and a thermally insulated gas mixing chamber is manufactured anew in the middle of the sample chamber and the detector chamber to make it possible to dilute a reactive gas and a water vapor gas having a high partial pressure. Consequently, it is possible to prevent moisture concentration to reduce an influence of water drops even in a high temperature and high humidity state at the time of humidity control and measurement.

The invention relates to a thermal physical property measuring device, which comprises a refrigerating machine (2) and a sealed vacuum cavity (1), wherein the refrigerating machine supplies cold energy to a sample to be measured so as to decrease the temperature of the sample to be measured to a measurement temperature, and the sealed vacuum cavity supplies a vacuum heat-insulating environment for measurement. The thermal physical property measuring device is characterized by further comprising a sealed sample chamber (8), a sample rack inserting pipe (6) and a sample rack (7), wherein the sealed sample chamber holds the sample to be measured; the sample rack inserting pipe is a tubular component; one end of the tubular component is a closed end; the other end of the tubular component is an open end; the closed end extends into the vacuum cavity (1); a first end of the sample rack is connected with the sample chamber (8); a second end of the sample rack is detachably and hermetically jointed with the open end of the sample rack inserting pipe (6); and the sample chamber (8) and the sample rack (7) which are connected mutually are suitable to be inserted into the sample rack inserting pipe (6). The device is mainly used for measuring the thermal physical property of the sample to be measured at a lower temperature, and compared with a conventional thermal physical property measuring device, the thermal physical property measuring device provided by the invention has the advantages that the sample is convenient and quick to replace, the test period is short, and the like.

The invention relates to a testing method for the anisotropic thermal-expansion coefficient of a continuous-fiber-reinforced resin-based composite material. The testing method comprises the following steps: (1) preparation of a sample, namely laying a plurality of optical-fiber Bragg grating strings among layers of prepregs of the resin-based composite material along 0-degree direction and 90-degree direction respectively, embedding the grating area from top to bottom by using small prepregs on the grating strings laid in the 90-degree direction with the fiber direction of the small prepregs being same as the optical-fiber direction, formed a lead groove in a side-wall frame plate of a mold, coating the surfaces of the side-wall frame plate of the mold and the lead groove with high-temperature-resistant high-molecular thin films, curing the composite material and demolding; (2) testing, namely leading out leads of the optical-fiber Bragg grating strings from an opening of a high-low-temperature thermostat, connecting the leads to an optical-fiber and grating demodulator, sealing the thermostat, heating according to the testing specifications and acquiring data; and (3) data processing. The testing method has the advantages that the optical-fiber Bragg grating strings for detecting the thermal expansion coefficient of the continuous-fiber-reinforced resin-based composite material are well protected and the obtained data is comprehensive, accurate and reliable.

The invention discloses an explosive body expansion coefficient testing device based on a liquid swelling method and a precise laser displacement sensor. The explosive body expansion coefficient testing device is composed of a volume metering system, a thermostat, a measurement control system and the like and can be directly used for measuring the volume increment of heat expansion of explosive and related materials and calculating the volume expansion coefficients of the explosive and related materials. When a testing system works, a swelling liquid flow system is constituted by a sample cavity in the volume metering system, a measuring thin tube, a sample cavity volume adjusting element and the like. The heat expansion volume increment of a sample is calculated through the liquid level height change displayed by the precise laser displacement sensor so that the volume expansion coefficient of the sample can be calculated. The explosive body expansion coefficient testing device has the advantages of being simple in operation, high in measuring accuracy, low in labor intensity and achieving the technical purpose that the explosive heat expansion coefficient is directly measured.

The invention relates to a civil engineering material volume change test instrument and a test method, in particular to a material volume change test device and test method in civil engineering. According to the test instrument, a sealing rubber ring is arranged in an annular groove, a base is covered with an upper cover, an air intake and exhaust hole is formed in the top end of the upper cover, one end of a probe thermometer is arranged in the upper cover, the other end of the probe thermometer is arranged outside the upper cover, a plastic pipe is arranged on the upper end face of the upper cover and communicated with a cavity, and a graduated glass pipe is communicated with the plastic pipe. The test method comprises the steps that first, a civil engineering material test piece is prepared; second, the volume of the civil engineering test piece before a test is calculated; third, the civil engineering test piece is installed; fourth, liquid is injected into the cavity; fifth, the temperature of the civil engineering test piece is measured in an initial temperature environment; sixth, the temperature of the civil engineering test piece is measured in a measuring temperature environment; seventh, the initial temperature and the measuring temperature of the test piece are measured, and the number of division of the test piece is calibrated; eighth, the volume variation theta Vt of the civil engineering test piece is calculated; ninth, the volume expansion coefficient lambda of the civil engineering test piece is calculated. The civil engineering material volume change test instrument and the test method are used for measuring the volume change situation of the civil engineering material.

A method for characterizing thermomechanical properties of an organic substrate includes the steps of: receiving an image of the substrate, the image including a geometric description of the circuit layers of the substrate; selecting a given one of the circuit layers for processing; converting the image to a 2-D FEM image of the given circuit layer; repeating the steps of selecting a given one of the circuit layers and converting the image to a 2-D FEM image of the selected layer until all of the layers have been processed; combining all of the 2-D FEM images corresponding to the layers to form a 3-D FEM image representing at least a portion of the substrate; determining a coefficient of thermal expansion (CTE), modulus and/or Poisson's ratio of the 3-D FEM image; and constructing a 3-D representation of the substrate as a function of the CTE, modulus and/or Poisson's ratio of the 3-D FEM image.

A method for determining an “effective” thermal coefficient of a machine comprises the steps of installing one or more temperature sensors (110) at various locations on the machine, positioning a first machine member (60) at a “known” reference location, relative to a second machine member (42), installing a linear position measuring device (120) to detect changes in position of the first machine member (60) relative to the second machine member (42) along a first axis of movement, periodically acquiring readings from each of the temperature sensors (110) and from the linear position measuring device (120) during a test cycle and compiling the temperature and linear position data into a table. A statistical correlation analysis is performed to determine which of the temperature sensors (110) experiencing changes in temperature are most linearly related to changes in the linear position of the first machine member (60) relative to the second machine member (42) and an “effective” coefficient of thermal expansion is thereafter determined as the rate of change of position, i.e. length, relative to change in temperature. The present method includes using the machine's “effective” thermal coefficient the calibrate the motion of the machine to compensate for the thermal characteristics thereof.

An object is to provide a method of detecting an amount of an axis displacement in a power transmission device using an automatic self-aligning engagement clutch, the method being capable of accurately detecting the amount of the axis displacement in the automatic self-aligning engagement clutch during an operation with a simple configuration. In a power transmission device configured to transmit a driving force to a driven body by allowing a rotary shaft of a first drive source to engage with a rotary shaft of a second drive source through an automatic self-aligning engagement clutch, an amount of an axis position variation of each of the rotary shaft of the first drive source and the rotary shaft of the second drive source are measured by non-contact sensors, and an amount of a relative axis displacement of the rotary shaft of the second drive source relative to the rotary shaft of the first drive source is detected on the basis of the measurement result of the amount of the axis position variation of each rotary shaft when the rotary shaft of the first drive source engages with the rotary shaft of the second drive source through the automatic self-aligning engagement clutch.

A calibration apparatus for calibrating a linear variable differential transformer (LVDT) having an armature positioned in au LVDT armature orifice, and the armature able to move along an axis of movement. The calibration apparatus includes a heating mechanism with an internal chamber, a temperature measuring mechanism for measuring the temperature of the LVDT, a fixture mechanism with an internal chamber for at least partially accepting the LVDT and for securing the LVDT within the heating mechanism internal chamber, a moving mechanism for moving the armature, a position measurement mechanism for measuring the position of the armature, and an output voltage measurement mechanism. A method for calibrating an LVDT, including the steps of: powering the LVDT; heating the LVDT to a desired temperature; measuring the position of the armature with respect to the armature orifice; and measuring the output voltage of the LVDT.

A method for electrically testing the thermal expansion coefficient of the film which is processed with polysilicon on the surface is presented basing on the suction phenomenon of the double-end clamped beam (1), the heat stress value generated in the double-end clamped beam (1) which is heated by the current according to the variation of the two suction voltage before and after the heating of the double-end clamped beam (1); and according to the variation curve of electric voltage in two ends of the double-end clamped-end beam (1) in the heating process recorded by the oscillograph, the variation value of the temperature on the heated double-end clamped beam is obtained; and at last according to the obtained heat stress value and the variation value of the temperature on the double-end clamped beam (1) the thermal expansion coefficient of the polysilicon film can be calculated with the relational expression.

The invention particularly relates to a high temperature hot dilatometer used for measuring a bulk specimen of corharts and a using method thereof. The hot dilatometer has the structure: a heating component (9) is arranged inside the body of a mill furnace (10) and the length of a soaking zone in the body of the mill furnace (10) is 200mm to 500mm; a soaking alundum tube (7) is arranged in the inner side of the heating component (9) and the tube mouth of the alundum tube (7) is arranged outside the furnace body (10); a temperature-controlling thermocouple (8) is arranged between the mill furnace body (10) and the soaking alundum tube (7) and a movable measuring device is arranged in the alundum tube (7); the using method of the device is that a temperature-time curved line of a designated material model (13) is measured and recorded firstly, and then a correcting value of the hot dilatometer is demarcated by using the temperature-time curved line and the alundum model, the dilatation of which is known; then a new model (13) of the same designated material is measured by using the demarcated hot dilatometer and thus the heat dilatation of the new model (13) of the designated material is measured out. The high temperature hot dilatometer has the advantages of convenient model manufacture and high measuring accuracy.

The invention discloses a measuring method and a measuring device for coefficients of thermal expansion. The measuring method comprises the following steps of: plating a layer of membrane which transmits light partially and reflects the light partially on upper and lower surfaces of a light transmission material to be measured respectively; heating the light transmission material; allowing a beamof monochromatic light to be incident to the light transmission material to be measured in the heating process, and reflecting the monochromatic light on the upper and lower surfaces of the light transmission material respectively, so that two beams of reflected light are interfered with each other; detecting the power of the interfered reflected light, finding a temperature value corresponding to the maximum value of the power of the reflected light, and determining the change period of the power of the reflected light in preset temperature intervals of the light transmission material; and calculating according to the change period to obtain the coefficients of thermal expansion of the light transmission material to be measured in the temperature intervals. By the measured method, the coefficients of thermal expansion of the light transmission material can be measured accurately, the test accuracy is relatively high, and system error caused by thermal expansion of sample frames and the like can be eliminated effectively; and due to the adoption of a single light source, a light path is simple, the cost is low, and the thermal expansion condition of each temperature interval can be reflected visually.

The invention relates to a method for determining a coefficient of thermal expansion. The method comprises the steps of determining a spectral peak movement amount of a to-be-detected sample caused by the variation of unit temperature to be recorded as ChiF; mixing the detected sample and polymer to obtain a mixture, and ultrasonically dispersing the mixture to obtain a composite material; determining a second spectral value of the composite material under a surface strain value by utilizing a strain determining device and a spectral system, linearly fitting the surface strain value and the second spectral value, determining the spectral peak movement quantity of the detected sample, which is caused by the unit strain and is parallel to the strain direction to be recorded as SO; determining the spectral peak movement amount of the detected sample in the composite material caused by the unit temperature variation by utilizing the spectral system to be recorded as ChiC; calculating the coefficient of the thermal expansion of the detected sample according to the following formula if the coefficient alpha E of the polymer is known: alpha F=alpha E-(ChiC-ChiF)/SO. The method is simple, convenient in determination and capable of rapidly and accurately determining the coefficient of the thermal expansion of the detected sample.

A thermal displacement correction device for a machine tool is provided with detection result determination unit configured to determine, based on an actual position and a reference position detected by position detection unit, whether or not the actual position is based on correct detection, correction error calculation unit configured to calculate a correction error in the actual position if it is determined that the result of detection is based on correct detection, and correction amount modification unit configured to modify a thermal displacement correction amount based on the correction error.

The invention discloses a determinator for thermal expansion coefficients of concrete. The determinator can be used for determining the thermal expansion coefficients of newly stirred concrete in the whole process from introduction of the concrete into a mould to coagulation and hardening of the concrete. The determinator comprises a movable container structure which is composed of polyformaldehyde plastic slabs and an insulation material, is assembled by four surfaces and facilitates dismounting of a concrete test piece after testing; the six polyformaldehyde plastic slabs, the insulation material and upper and lower aluminum plates form a cuboid enclosed space which is used for accommodating a newly stirred concrete test piece; sides of the upper and lower aluminum plates opposite to the contact sides of the upper and lower aluminum plates and the test piece are all full of semiconductor chilling chips, and metallic cooling fins are used to evacuate heat of the semiconductor chilling chips; the upper and lower aluminum plates and upper and lower plastic slabs respectively form an enclosed cavity which encapsulates the metallic cooling fins; the upper and lower enclosed cavities are connected with a circulating pump through water pipes and are filled with water so as to form water circulation loops; furthermore, a temperature sensor is placed in the concrete test piece to measure the temperature of the concrete test piece, and high precision displacement sensors are installed at the center of the polyformaldehyde plastic slabs and the insulation material at the left and right sides to measure expansion shrinkage deformation of the concrete when the temperature of the concrete changes.

In a control equipment 10, shaft-misalignment amount of a shaft 3a of a gas turbine 3 and a shaft 5a of a steam turbine 5 is measured and speed-increase ratio of rotation speed and heat soak time of the steam turbine 5 are set in accordance with the measured shaft-misalignment amount so as to have the shaft-misalignment amount stay within a permissible range when a clutch 7 connects the shafts 3a and 5a.