Wavelength:
The wavelength of radio waves is usually expressed by frequency: 300 khz ~ 30 GHz.
Microwave 1 mm-1 m
Infrared 0.76- 1000μ m
Visible light:
Red 640-780 nm
Orange 640-6 10 nm
Yellow 610-530 nm
Green 505-525 nm
Blue 505-470 nm
Purple 470-380 nm
Ultraviolet 0.0 1-0.4μ m
X-ray 0.0 1- 10 nm
Gamma rays are shorter than 0.02 nm.
Use:
Radio waves: such as radio, wireless TV, walkie-talkie, etc.
Microwave: It is widely used in various communication services, including microwave multiplexing communication, microwave relay communication, mobile communication and satellite communication. Modern radar is mostly microwave radar, as well as radio radiometer, microwave oven and so on.
Infrared: infrared is widely used in monitoring equipment, and generally comes with near-infrared light source. The system design is very similar to visible light. Far infrared is mainly used in military affairs.
Visible light: it is the light of various colors that we can see at ordinary times, which is too widely used.
Ultraviolet rays: fluorescent lamps, fluorescent lamps and black lights used to trap and kill pests in agriculture all use ultraviolet rays to excite fluorescent substances to emit light.
X-ray: it is commonly used for perspective in medicine and flaw detection in industry. X-ray can excite fluorescence, ionize gas and make photosensitive latex sensitive, so X-ray can be detected by ionization meter, scintillation counter and photosensitive latex sheet.
γ-ray: γ-ray has strong penetrating power and can be used for flaw detection or automatic control of assembly line in industry. Gamma rays are lethal to cells and are used to treat tumors in medicine.
Extended data:
According to the mode of electromagnetic wave generation, it can be divided into three parts:
High frequency region (high energy radiation region)
These rays include x-rays, gamma rays and cosmic rays. They are produced by bombarding some substances with charged particles. These radiations are characterized by high quantum energy, weak fluctuation and strong particles when interacting with matter.
Long wave region (low energy radiation region)
These include radiation with the lowest frequencies, such as long waves, radio waves and microwaves. They are generated and received by an electron beam tube with capacitance and inductance vibration structure, that is, energy oscillates between capacitance and inductance. Their interaction with matter is more characterized by volatility.
Intermediate zone (intermediate energy radiation zone)
These include infrared radiation, visible light and ultraviolet radiation. This part of the radiation comes from the movement of atoms and molecules, and in the infrared region, the radiation mainly comes from the rotation and vibration of molecules; In the visible and ultraviolet regions, radiation mainly comes from the transition of electrons in the atomic field. This part of radiation is collectively called optical radiation, which shows fluctuation and particle duality in the interaction with matter.
The electromagnetic spectrum of various radiation sources in nature is quite rich and extensive. The electromagnetic spectrum of X-rays, ultraviolet rays, visible light, infrared rays and microwaves is directly related to photoelectron imaging technology, and their characteristic parameters are wavelength λ, frequency f and photon energy E..
The relationships between them are f=c/λ, E=hf=hc/λ, E= 1.24/λ, where the units of e and λ are eV and μ m respectively, and h is Planck constant (6.6260755x10J s). C is the speed of light, and the approximate value in vacuum is 3x10m/s. In engineering practice, different measurement units of spectral parameters are adopted according to different needs and habits.
For X-rays, ultraviolet rays, visible light and infrared rays, microns and nm are commonly used to represent wavelengths; For the radio spectrum, the frequency and wavelength are expressed by Hz or m respectively; For high-energy particle radiation, eV is often used to represent energy.
References:
Baidu encyclopedia-electromagnetic spectrum