31results about How to "Low measurement disturbance" patented technology

The application relates to the technical field of insulating material performance testing, in particular to a VFTO test apparatus for a 500-kV GIS basin type insulator. In practical operation, surface charges are accumulated on the surface of the GIS basin insulator to cause distortion of a local electric field, so that the insulator surface flashover under VFTO is caused; and thus the interference on the space electrical field measurement is caused, so that the measurement error is increased. The VFTO test apparatus is composed of an electric field measurement unit, a data processing unit and an energy supply unit. The electric field measurement unit consists of a positive-pressure container module, a high-voltage electrode module, a to-be-tested basin type insulator module and sensor modules; the data processing unit includes a data calculation module and a display module; and the energy supply unit includes a high-voltage power supply module connected to the high-voltage electrode module. The test apparatus has advantages of small measurement interference, small error, and high precision.

The invention relates to a gas concentration detection system based on a wavelength modulation spectrum. A sine wave signal output end of a first signal generator of the system is connected with a summator; a triangular wave signal output end of a second signal generator is connected with the summator; the signal output end of the summator is connected with a pulse width modulator; the signal output end of the pulse width modulator is connected with a laser drive; the laser drive signal input end of the laser drive is connected with a distribution type feedback laser; the laser signal output end surface of the distribution type feedback laser faces to the laser signal incidence port of a gas concentration detection gas chamber; the signal input end of a laser detector faces to the laser signal outgoing port of the gas concentration detection gas chamber; the laser sensing signal output end of the laser detector is connected with a signal input end of a processor; the cosine wave signal output end of the first signal generator is connected with a locking amplifier; the signal output end of the locking amplifier is connected with the processor; the triangular wave signal output end of the second signal generator is connected with the processor. By adopting the gas concentration detection system, the concentration of gases can be accurately measured.

The invention discloses a surface enhanced Raman spectrum detection method for a gene based on CRISPR/Cas12a protein. Target virus nucleic acid, Cas12a and crRNA are utilized to form a ternary complex, and a substrate (i.e., ssDNA) in a cleavage system is opened. The ssDNA is a bridging complementary sequence of DNA1 and DNA2 on a probe 1 and a probe 2. Whether the probe 1 and the probe 2 are bridged or not can cause change of SERS signals, so that whether a sample to be detected contains target nucleic acid or not can be known. Accurate and rapid detection of viral nucleic acid can be realized by using the specific crRNA. The CRISPR@Cas12a is combined with the SERS technology, so that the biggest advantage is that a tedious modification preparation process is avoided, and the SERS probe can stably exist for a long time. According to the method, the key step of signal amplification occurs on a solution phase of ssDNA instead of an interface of a nano assembly, so that the method is more stable and higher in trans-cutting efficiency, the sensitivity and repeatability of the detection method can be guaranteed, and the method has important significance in early monitoring, diagnosis, prevention and control of diseases.

The invention provides a technical scheme of a vibration measurement device for a laser interference rotor and a measurement method thereof. The scheme can simultaneously detect bending vibration and torsional vibration of a high-speed rotor based on beat frequency generated by laser Doppler effect, realizes frequency modulation measurement of a vibration signal under the condition of not using an expensive frequency shift device, and precisely distinguishes the directions of bending vibration and torsional vibration, has very strong anti-environment disturbance capability, and is low in manufacturing cost. The scheme belongs to non-contact measurement, the motion state of the to-be-measured rotor is free from interference, the accuracy in measurement is high, the response speed is fast, the dynamic range is wide, and the measurement can be performed at a further distance. The processing error of the rotor and measurement interference of torsional vibration and bending vibration from other vibration states are small.

The invention discloses a flow induction noise isolating and muffling device, relates to the field of noise control, and in particular relates to an isolation device for two flow water noise sources. The flow induction noise isolating and muffling device comprises an inlet pipe (1), an outlet pipe (2), an air exhaust port (3), a pot body (4) and a multipore plate (5). An interference muffling technology, a variable-frequency attenuation muffling technology and a multipore noise absorption technology are comprehensively used, so that mutual interference between the two noise sources is isolated; and aiming at a multi-frequency noise muffling situation, a good noise reduction effect is achieved. The flow induction noise isolating and muffling device is high in muffling and noise isolation performance, is convenient to process and has a small volume.

The invention relates to a method for measuring a body phase angle. The method comprises the following steps: selecting a frequency f1 below 200khz as a first acquisition frequency of body impedance, and acquiring a first body impedance value z1; selecting a frequency f2 above 200khz as a second group of acquisition frequencies of the body impedance, and acquiring a second body impedance value z2; calculating a first estimated value of body capacitance impedance corresponding to the frequency f1, namely subtracting z2 from z1 to acquire zc; repeating the steps S1, S2 and S3, and collecting n groups of body capacitance impedance first estimated values of different persons as a fitting data set; applying a fitting algorithm through the fitting data set, to obtain a k value and a b value in a body capacitive reactance value estimation model ze which is the sum of k zc and b; repeating the steps S1 and S2 to obtain a first estimated value zc of the body capacitive reactance, and applying the body capacitive reactance estimation model to obtaining a second estimated value ze of the body capacitive reactance; and calculating a body phase angle corresponding to the frequency f1 as arctan (ze/z2).

The invention discloses a method for measuring a primary ray spectrum of an X-ray tube. The method comprises the following steps: placing the X-ray tube, a first aluminum plate and a detector in sequence; after the X-ray tube is arranged, a spectrogram P1 is obtained through a detector; taking away the first aluminum plate, replacing the first aluminum plate with a second aluminum plate with the thickness of D2, and retesting to obtain a spectrogram P2; according to the energy calibration coefficient of the detector, the channel numbers of the spectrogram P1 and the spectrogram P2 are converted into energy values, and a spectrogram P3 is obtained; obtaining a spectrogram P4 of the rays emitted by the X-ray tube before being absorbed by the first aluminum plate or the second aluminum plate according to the absorption of the rays by the first aluminum plate and the second aluminum plate; and according to the beryllium window of the X-ray tube and the absorption of the air to the rays, obtaining a spectrogram P5 of the rays emitted by the X-ray tube before the rays are absorbed by the beryllium window and the air. According to the measurement method, the aluminum plate is adopted as a ray attenuation medium of the X-ray tube, the measurement path is short, interference is reduced in a differential mode, the measurement accuracy is high, and use is convenient.

The invention relates to the technical field of measuring the weight center of gravity of an unmanned aerial vehicle, and discloses a weight center of gravity measuring device which comprises a connecting piece used for being connected with the unmanned aerial vehicle; the roller mechanism is provided with a fixing part and a roller part, the fixing part is used for being connected with the connecting piece, and the fixing part and the roller part are connected through a rotating pair or a spherical pair or a rolling pair; the bearing piece is provided with a bearing part and a supporting part, and the bearing part is used for bearing the roller mechanism and is connected with a roller part of the roller mechanism through a rolling pair; the bottom of the bearing part is fixedly connected with the supporting part; the weighing sensor is used for being connected with the supporting part and measuring the unremembered weight; and the jacking mechanism is used for fixing the weighing sensor and adjusting the height of the weighing sensor. The interference of the lateral force generated by the stress shape edge of the unmanned aerial vehicle on the measurement accuracy of the weight center of gravity is avoided.

The invention belongs to the technical field of oil field drilling, and discloses a PMSM degradation experiment device in an underground environment and a motor service life prediction method. The method for predicting the residual life of the motor in the underground environment comprises the following steps of: acquiring a measurement signal of a permanent magnet synchronous motor by using a sensor, performing spectral entropy analysis on a stator three-phase current signal of the permanent magnet synchronous motor, and extracting a spectrum complexity change condition of the stator three-phase current signal in a degradation process; wavelet time-frequency band energy conversion is carried out on the vibration signals, and energy changes of the vibration signals in the degradation process are extracted; the collected temperature, sound wave, torque and rotating speed, the extracted stator three-phase current signal and the extracted vibration signal are divided into a training set, a test set and a verification set, and the data sets are transmitted to a network to train the network. According to the method, the real-time residual service life prediction of the permanent magnet synchronous motor of the underground drilling communication tool can be realized, and the operation reliability and the working safety of an underground system are improved.

Disclosed is an electric energy metering device. A processor and a control unit connected with the processor are arranged on a machine cabinet. A voltage transformer is arranged above the control unit on the machine cabinet. A voltage input end of the control unit is connected with a voltage binding post arranged on the machine cabinet. The voltage binding post is connected with a secondary winding of the voltage transformer. The voltage transformer is connected with a voltage wire inlet terminal arranged on the machine cabinet. The processor, the control unit and the voltage transformer are installed in the machine cabinet, the voltage transformer is arranged above the control unit, and high voltage passes through the voltage transformer through the voltage wire inlet terminal, and then is input to the control unit through the voltage binding post. The whole distribution is convenient for wire distribution and wire connection, current wire distribution space is compressed, and meanwhile metering interference is reduced, and accuracy of detected data is improved.