41results about How to "Improve measurement uncertainty" patented technology

The present invention relates to absolute distance measurement method and system using an optical frequency generator. The absolute distance measurement method using the optical frequency generator includes (a) generating a plurality of different stabilized wavelengths by using the optical frequency generator; (b) obtaining an initial estimation value of a distance to be measured by using a frequency sweeping interferometer; (c) analyzing an uncertainty range of the obtained initial estimation value; (d) measuring excess fraction parts of the different wavelengths by analyzing interference signals for each of the wavelengths; (e) determining integer parts for each of the different wavelengths within the uncertainty range of the initial estimation value; and (f) measuring an absolute distance to be measured by using the excess fraction part and the integer parts for each of the different wavelengths.

The invention relates to the technical field of the detection and the calibration of a hydrometer, in particular to a calibration device and method for calibrating a petroleum hydrometer. The calibration device comprises a fixed mount, a thermostatic bath and a scale, wherein the thermostatic bath is arranged in the fixed mount, the scale is arranged on the top surface of the fixed mount, a lifting rope is arranged below the scale, a glass measuring cylinder is arranged in the thermostatic bath, the glass measuring cylinder comprises a main measuring cylinder and an auxiliary measuring cylinder, the main measuring cylinder is communicated with the auxiliary measuring cylinder by a liquid level regulating device, and a thermometer is arranged in the main measuring cylinder. The invention realizes the switching among different calibration marking points of the hydrometer based on the vertical movement of the liquid level of the reference liquid, so that the liquid level of the referenceliquid can be tangential to the required calibration marking point, thereby meeting the calibration requirements of the hydrometer, filling in the gap that a low-range petroleum hydrometer can not becalibrated, expanding the calibration range of the petroleum hydrometer, improving the calibration automation degree, enhancing the calibration efficiency, reducing the measuring error and improving the calibration uncertainty level.

The invention provides a self intermodulation inhibition method for a transmission passive intermodulation (PIM) test. A phase position of a PIM product is measured through a PIM reference channel, and in allusion to the transmission PIM test of appliance parts such as antennae, a method for inhibiting transmission self PIM of a test system is provided and a novel method for inhibiting reflection self PIM can be provided. By means of the scheme, reflection self intermodulation and system transmission self intermodulation can be inhibited, thereby, excessive demands for intermodulation features of loads are not required, meanwhile, interference of transmission PIM and reflection PIM can be measured, and the dynamic range and the measurement uncertainty of the transmission PIM test of the system can be improved.

The invention relates to the technical field of the transmission of metering and testing standard quantity values, and particularly relates to a standard substance for calibrating magnification of an industrial CT system. The standard substance for calibrating magnification of an industrial CT system is characterized in that: a substrate of the standard substance is provided with a counter bore and a pilot hole; inside the counter bore is provided a sheet with a through hole, wherein the thickness of the sheet is 0.1 to 0.3 mm, the sheet is made of metal platinum alloy, and the aperture of the through hole is 0.2 to 0.5 mm. According to the invention, a scanning electron microscope with a certified standard substance is employed for measuring, so a certified standard substance for calibrating magnification of an industrial CT system is obtained, thereby solving the problem of lack of calibration in metering and testing magnification of the industrial CT system, providing a trace valueto the source for an image length value of the calibrated industrial CT system with uncertainty of a given confidence interval attached; therefore, a three-dimensional image of the calibrated industrial CT system has traceable length values.

The invention discloses an emissivity coefficient self-calibration device and method for a multi-spectral radiation temperature measurement system, comprising a wide-spectrum light source and an incident collimating lens group and an outgoing collimating lens group sequentially arranged on the outgoing light path of the wide-spectrum light source. The measuring flame is arranged between the incident collimating lens group and the outgoing collimating lens group. The present invention sets an emissivity coefficient self-calibration system on the same path that the multi-spectral radiation temperature measurement system passes through to measure the flame. By recording the spectral parameters of the wide-spectrum light source, the flame, and the combined flame of the wide-spectrum light source, the parameters obtained at different wavelengths are obtained. The flame emissivity coefficient is used in the parameter correction of the multi-spectral radiation temperature measurement system, which overcomes the model error in the correction of traditional theoretical calculations and improves the measurement uncertainty.

The invention provides a device for measuring the air refractivity based on a dispersion interference method and a measuring method of the device. The device comprises an optical frequency comb with locked repetition frequency, a slab beam splitter with a splitting ratio of 50:50, a vacuum tube with a certain length, a hollow pyramid subjected to surface gold plating, and a spectrum analyzer used for recording an interference spectrum, wherein the optical frequency comb with locked repetition frequency has multiple stable-frequency longitudinal molds and is capable of acquiring the dispersion characteristics of the air refractivity; the vacuum tube is internally vacuumized and is externally communicated with air, so that relative measurement for the air refractivity can be realized under a condition of avoiding air extraction and air inflation, and relatively high measurement uncertainty can be obtained. The invention further discloses the measuring method of the device. The measuring device has the advantages of simple device, short measurement period, good stability and the like, and can be used for correcting the air refractivity in real time during precise length measurement.

The invention relates to a measuring method of the mid-infrared light signal intensity in wide temperature environment. According to the method, firstly, a measuring device is built, the measuring device comprises a mid-infrared light guide detector, a driving circuit and a signal collection recording instrument, wherein the driving circuit comprises an instrument amplifier unit and a constant flow source unit; secondly, the dark resistance value and the response rate value of the mid-infrared light guide detector at application environment temperature are obtained through measurement, and in addition, the balancing resistance and the magnification time parameter in the driving circuit are determined; and finally, the mid-infrared light signal intensity is obtained through calculation through the voltage signal and the monitored work temperature. The measuring method has the advantages that the optimal solution of the balancing resistance and the circuit magnification times is obtained according to the parameters of the dark resistance valve, the work voltage and the like of each detector at the wide temperature range end point, the output signal amplitude and the measurement dynamic range of a constant flow source type mid-infrared detection circuit are improved, the characteristics of concise step and convenience in realization are realized, and the measuring method can be used for the batch design of the mid-infrared detection circuit.