Gauss meter - Tesla meter application field

Gauss meter, Tesla meter application field
------ Electromagnetic field definition and introduction
Electricity and magnetism are phenomena that exist in nature all the time, such as lightning and magnets. Humans have known for a long time that they can use electricity and magnetism to improve and enrich their lives. Besides of the existence of natural electromagnetic field, people for the convenience of life developed many electrical appliances, such as the commonly used mobile phones, TV, hair dryer, induction cooker, microwave ovens, computers, air conditioning and other household appliances, even the MRT, electric train, power transmission and transformation equipment and other public facilities, convenient life also added some artificial electromagnetic field.

Question 1: what is the electromagnetic field measuring instrument -- gaussian meter, tesla meter, fluxmeter. The electromagnetic field is the electric field and the magnetic field collectively called.
The term "field" refers to an area of space where forces are felt by any object that enters the area. For example, we live in the earth's gravitational field, we live in the magnetic field of the earth, and we are surrounded by strong electric fields during lightning.
Question2: can the electric field be explained in more detail?
The existence of electric field is often found in life, such as the explosive sound that takes off the sweater in winter, and the electric shock that touches the handle of the door. These are the electrostatic phenomena generated by friction. In the use of electricity, there is an electric field around wires or electrical equipment as long as there is a voltage. The electric field is generally measured in kilovolts per meter (kV /m).

Question 3: can we give a more detailed explanation of the magnetic field?
Put a magnet under the cardboard, sprinkle iron powder on the cardboard, and you will find that the two ends of the magnet are connected by several circles of stripes, this is the magnetic field. In the use of electricity, a magnetic field is also generated around a wire whenever a current passes through it. The magnetic field is expressed in units of tesla (T) or gauss (G) or milligauss (mG) or microtesla (μt).
1 tesla =10,000 gauss
1 gauss =1,000 milligauss
1 microtesla =10 milligauss
Question 4: Will the electromagnetic field decay? Can it be blocked
The intensity of electric and magnetic fields will decrease rapidly with the increase of the distance from the source. If the voltage and current of the source disappear, the electromagnetic field will also disappear. The electric electromagnetic field (60Hz) belongs to the extremely low frequency electromagnetic field (30 ~ 300Hz), which changes slowly, and can be discussed separately from the electric field and magnetic field.
Electric field is easy to shield, such as metal shell, reinforced concrete, trees and human skin can be quite good shielding effect. Power equipment such as transformers, cables and so on mostly have metal shell, its outside almost no electric field, all the equipment in the house type substation are in the reinforced concrete building, the electric field shielding is better, and the human skin has excellent shielding of the electric field (about attenuation 100 million times), into the human body electric field is almost zero. Therefore, in the study of the effect of electromagnetic field on human health (epidemiology), the electric field has been excluded, and the magnetic field is the dominant field.
The magnetic field is almost impossible to shield, but the magnetic field generated by the same current in the opposite direction cancels out, so a three-phase power line with the same current produces a much smaller field than a single-phase power line.