At present, the more mature and widely developed metrological science and technology fields are: geometric quantity (length), thermal engineering, mechanics, electromagnetics, radio, time frequency, acoustics, optics, chemistry and ionizing radiation, namely the so-called "ten major metrology".
Geometric quantity measurement characterizes the geometric characteristics of tangible objects and the spatial position of particles. It involves specific measurements such as wavelength, line measuring tools, gratings, sensor synchronizers, gauge blocks, polyhedrons, angles, etc. Rulers and steel tape measures are commonly used in life, and satellite positioning systems are widely used in military and transportation, etc., are all research results of length measurement.
The objects of thermal engineering measurement are parameters such as temperature, pressure, vacuum, flow, material quantity and material level that are commonly used in thermal processes in industrial production. For example, the verification and calibration of ordinary glass liquid thermometers and infrared thermometers are directly related to doctors' judgment on whether patients have fever, and provide technical support for the fight against SARS.
Mechanical metrology involves the measurement of mass, force value, density, capacity, torque, mechanical power, pressure, vacuum, flow, displacement, velocity, acceleration, hardness, etc. For example, the accuracy of fair scales, electronic price scales, water meters, gas meters, taxi meters, etc. on the market is guaranteed by mechanical metrology.
The professional fields involved in electromagnetic metrology include impedance and electric quantity of DC and DC, precision AC and DC measuring instruments, analog-to-digital/digital-to-analog conversion technology, magnetic flux, magnetic materials and magnetic recording materials, magnetic measuring instruments and quantum metrology, etc. There are many contents of electromagnetic metrology that are closely related to people's lives, such as the accurate angle of household electric energy meters, etc.
Radio metrology includes the measurement of electromagnetic energy parameters (such as voltage, current, power, electric field strength, power flux density and noise power spectrum density); the measurement of characteristic parameters of electrical signals (such as frequency, wavelength, amplitude modulation coefficient, frequency deviation, distortion coefficient and waveform characteristic parameters); the measurement of circuit elements and material characteristic parameters (such as impedance or admittance, resistance or conductance, inductance and capacitance, Q value, complex dielectric constant, loss angle) and the measurement of device and system network characteristic parameters (voltage standing wave ratio, reflection coefficient, attenuation, gain, phase shift). For example, the accuracy of multimeters used for electrical appliance repair, the measurement of mobile phone transmission power, etc.
Time and frequency measurement is used to measure frequency values and time intervals. The main service areas are: communications, aerospace, national defense, electronics, home appliances, medical, scientific research, television, services and other fields. Such as time reporting services, various types of (mobile phones, telephones, parking) service timing, etc.
Acoustic metrology is the study of the measurement of sound pressure, sound intensity, sound intensity, sound power and loudness, hearing loss and other quantities. Such as noise measurement, traffic noise, environmental noise, architectural acoustics, and electroacoustic measurements have played a positive role in the development of scientific research, production, national defense and the national economy.
The objects of optical metrology include light sources, light detectors, optical media, optical components and optical instruments. Among them, light sources include natural light sources, artificial light sources, lasers, etc. Optical metrology involves parameters such as radiation intensity, radiation illumination, and radiation brightness. For example, the measurement of the brightness of lights and car lights in daily life, the measurement of color, etc.
Chemical metrology mainly focuses on the measurement of chemical properties of substances such as heat, viscosity, density, conductivity, and turbidity. Chemical metrology is closely related to the daily life of the people. For example: the purity of drinking water, the content of harmful substances in food, etc.
Ionizing radiation measurement refers to the measurement of relevant parameters of o, 8, y, x and neutron radiation. Ionizing radiation measurement involves medical, industrial, agricultural, military, environmental monitoring and other aspects. Such as medical X-ray machines, CT machines, drill-60 treatment machines, X-knives and other equipment, industrial X-ray flaw detectors, nuclear belt scales, agricultural garlic irradiation processing, water quality testing for environmental monitoring, and prohibited items detectors used in customs, stations, and docks.
