33 results about "Dilatometer" patented technology

The invention discloses a dilatometer. The dilatometer at least comprises a base, a container arranged on the upper side of the base, a vertical dial indicator and a horizontal dial indicator, wherein the container consists of a base plate and a side wall; a cuboid soil sample is arranged in the container; a vertical force measurement plate is arranged on the upper side of the cuboid soil sample; a horizontal force measurement plate capable of moving along the normal direction of more than one side wall of the cuboid soil sample with the dilation of the soil sample is leaned on the side wall; the vertical dial indicator and the vertical force measurement plate are contacted with each other tightly and vertical to each other; and the horizontal dial indicator passes through a dial indicator insertion hole formed in the side wall of the container and is contacted with the horizontal force measurement plate tightly and vertical to the horizontal force measurement plate. By the dilatometer, a user can observe the dilated deformation of the soil sample in vertical and horizontal directions at the same time.

The invention discloses a dilatometer for measuring the expansive force by a constant volume method, and relates to geotechnical test apparatuses. According to the structure of the dilatometer, a fixing system is connected with a measuring system, the fixing system comprises a fixing base, circular steel columns, a square crossbeam with a hole, a knob, a lower permeable stone, an upper permeable stone, a cutting ring fixing cylinder, a cutting ring, a nut, and a gasket, and the measuring system comprises a pressure sensor, a data display meter, a computer, and a dial gauge. The dilatometer is advantageous in that 1) constant volume: the volume of a soil sample in the whole test process is invariable; 2) high precision: the pressure sensor is advantaged by high precision and large measuring range, and the precision of test results is improved; 3) wide range: the dilatometer is applicable to measurement of the change of the expansive force in the soaking process of the soil sample and with the change of the environmental humidity condition and the test of the expansive force under the temperature control; and 4) the structure is good, the installation is convenient, the operation is simple, and the data display is visual.

The invention relates to an expansive soil two-dimensional dilatometer, and can effectively solve the problem that the expansion deformation and expansion force in both the vertical direction and the lateral direction cannot be measured at the same time by the conventional dilatometer. The expansive soil two-dimensional dilatometer adopting the technical scheme is characterized by comprising a testing stand and a pressure chamber arranged on the testing stand, wherein the pressure chamber adopts a square tubular structure which is provided with a left end opening and a right end opening, and is defined by a bottom plate and a top plate arranged in an up-and-down spaced manner and a front clamping plate and a back clamping plate arranged in a front-and-back spaced manner; the space jointly defined by two side press plates, a pressurizing plate, the bottom plate, the front clamping plate and the back clamping plate forms an accommodating space for a test soil sample; sliding mechanisms are connected with a loading mechanism arranged on the testing stand through flexible ropes; a first displacement sensor is arranged on a pressure transfer plate to be used for measuring the vertical displacement of the pressure transfer plate; second displacement sensors are arranged on force transfer rods to be used for measuring the horizontal displacement of the force transfer rods. The expansive soil two-dimensional dilatometer is novel and unique in structure, simple, reasonable, easy to produce, simple to operate, and low in cost; a test of expansion deformation or expansion force can be carried out by only one instrument, so that the use is convenient, and the effect is good.

The invention provides an expansion curve analysis method for a steel critical point test and a use thereof. The expansion curve analysis method comprises drawing an expansion curve by temperatures T as horizontal coordinates and expansion amounts L as vertical coordinates in data recorded by a dilatometer, respectively carrying out linear fitting on linear expansion parts at the left and right sides of the expansion curve to obtain straight line equations L alpha and L gamma of the corresponding expansion amounts and temperatures, calculating a high temperature phase (gamma phase) volume fraction X gamma, drawing a curve by T as a horizontal coordinate and X gamma as a vertical coordinate, selecting an appropriate critical volume fraction C according to concrete experimental requirements, finding temperatures T respectively corresponding to two points with X gamma equal to C and X gamma equal to 100%-C from the X gamma-T curve, wherein the temperatures T are used as critical points, and expressing test results comprising the transformation critical points and critical volume fractions C. The expansion curve analysis method solves the problem that the tangent method, the extremum method, the angular cut method and the average method have undefined physical significance or easily is influenced by a subjective factor, and improves an objective quantification degree of expansion curve analysis.

The invention discloses a measured value correction method of a dilatometer, which comprises the following steps: (A) a standard sample that has the similar characteristics and the same size with a test sample is chosen, and heat expansion coefficients of the standard sample at different temperatures are measured and recorded under a selected temperature change condition; (B) heat expansion coefficients of the test sample at different temperatures are measured and recorded under the same condition; and (C) average coefficient of linear expansion of the test sample at different temperatures is computed according to a formula. The measured value correction method of the dilatometer ensures the accuracy of detected results and raises the sensitivity of the dilatometer.

The invention discloses a determination method of a dilatation coefficient of glass. The method comprises the following step: conveying a sheet-shaped or block-shaped glass sample to be detected into a dilatometer to determine the dilatation coefficient. The method is characterized in that before the glass sample is conveyed into the dilatometer, the method further comprises the step of pre-treating the glass sample to be detected; the pre-treatment method comprises the following steps: after fusing the glass sample to be detected, drawing the glass sample into a glass wire with the diameter of phi+/-0.1mm, and then carrying out annealing treatment on the glass wire, wherein phi is 1.5mm-6mm. The method provided by the invention has the advantages of low sample treatment difficulty, short sample preparation time, and high stability and accuracy of testing the dilatation coefficient.

The invention provides a method for measuring the firing temperature range of an electrotechnical porcelain green body by using a high-temperature dilatometer, which comprises the following steps of: performing differentiation on a linear expansion ratio curve of the electrotechnical porcelain green body to obtain a first-order differential curve of the linear expansion ratio curve; and calculating a thermal expansion coefficient curve by the linear expansion ratio curve through a formula 1 and a formula 2 jointly, wherein in the formula 1, alpha= dL/L0*[1/(th-t0)]+alpha0, and in the formula 2, A=dl/L0*100+alpha0(th-t0)*100; the maximum temperature in corresponding coordinates within a last decreasing region of the first-order differential curve is a minimum firing temperature point of the electrotechnical porcelain green body; and the maximum temperature in corresponding coordinates within a last decreasing region of the thermal expansion coefficient curve is a maximum firing temperature point of the electrotechnical porcelain green body. In the method, a thermal expansion test of the green body is completed at a high temperature by modern scientific research instruments with advanced testing means, so the time period is short, the accuracy is high, the analysis is convenient, and artificial influencing factors are fewer.

The invention discloses a multi-boundary-condition dilatometer and a soil expansion test method. The multi-boundary-condition dilatometer comprises a lower supporting platform, an upper fixed frame, a boundary condition simulating mechanism, a sample carrying chamber and a measuring mechanism. The upper fixed frame, the boundary condition simulating mechanism and the sample carrying chamber are all mounted on the lower supporting platform, and the measuring mechanism is mounted in the upper fixed frame. An equal-rigidity flexible boundary simulating unit is designed, meanwhile, a constant-size and constant-stress boundary simulating unit is integrated, and compared with a traditional dilatometer, a test can be carried out under multiple boundary conditions, and the influence of the boundary conditions on the expansion performance of soil is analyzed. Different test paths can be designed, and the influence of the test paths on the expansion performance of soil can be analyzed. A sensing measuring device and a data collecting device are adopted, testing precision is high, and data collecting are convenient. The device is simple and novel in structure, easy and convenient to operate, small in influence from human factors, low in cost and reliable in data.

The invention discloses a method for measuring porosity of a catalyst layer of a proton exchange membrane fuel cell. The method comprises the following steps: step 1, taking a nonporous and noncompressible thin film material with certain flexibility as a substrate of the catalyst layer, and depositing catalyst slurry on a thin film substrate to form the catalyst layer; step 2, putting the thin film material into a dilatometer of a mercury injection apparatus, determining pore size distribution of the thin film material, and calibrating the real volume of the dilatometer; step 3, putting the substrate loaded with the catalyst layer into the dilatometer of the mercury injection apparatus, and measuring aperture structure information of the catalyst layer; and step 4, according to the measured data, calculating a volume of the catalyst layer VCL and a mercury filling volume Vpore, and calculating the porosity of the catalyst layer according to a formula described in the specification. The method disclosed by the invention has the advantages that influence of substrate deformation and pore size distribution thereof on the porosity of the catalyst layer can be completely separated, the porosity of the catalyst layer can be rapidly and accurately calculated, practicability and experiment accuracy are good, and accuracy of measuring the porosity of the catalyst layer can be improved.

An ultrasensitive ratiometric capacitance dilatometer and related methods are described. The dilatometer provides a capacitance measurement based on a ratiometric capacitance, or the capacitance ratio measured between two or more parallel plate capacitors of the dilatometer. In this regard, an absolute capacity bridge is not required, and even more advantageously, the effects of adsorbed gas are greatly reduced compared to conventional dilatometers. The ratiometric capacitance dilatometer provides a symmetrical configuration, which reduces the effects of temperature gradients. Moreover, certain embodiments provide a “v-groove design”, wherein a first parallel plate capacitor forms an angle with a second parallel plate capacitor of the dilatometer along a key centerline of the dilatometer cell, which improves manufacturability due to simpler grinding, metalizing and assembly.

The invention discloses a measurement method for bulk metallic glass structural relaxation activation energy. The method includes representation of bulk metallic glass structural relaxation behavior and measurement of relaxation activation energy. Representation of bulk metallic glass structural relaxation behavior includes cutting, grinding and polishing of a bulk metallic glass sample, and thermal insulation in a thermal dilatometer for measurement of the length change of the sample in structural relaxation. The measurement method of structural relaxation activation energy includes fitting processing of the sample's length change curve data of bulk metallic glass in isothermal structural relaxation, and calculation of the bulk metallic glass's relaxation structural activation energy with quasi-steady state relaxation state at different isothermal temperatures. According to the method provided by the invention, the bulk metallic glass sample is placed in the thermal dilatometer for thermal insulation, thus being conducive to in situ observation of the structural relaxation process, convenient calculation of the structural relaxation activation energy, and exploration of the metallic glass structural relaxation internal mechanism.