Bottom box: look and smell. In addition to looking at the thickness, hardness, and flame retardancy, the judgment standard can also be smelled with the nose. The most high-end is made of nylon material, which is odorless; the mid-range is made of plastic, which has a normal plastic smell; the low-end and inferior ones are made of waste plastics and recycled plastics, which have a peculiar smell.

Look at the appearance of the switch panel. The panels of high-quality switches and sockets should be made of high-grade plastic products, which look uniform in material and have a smooth and textured surface. Panel materials are mainly divided into two types: PC (bullet-proof plastic) and ABS (engineering plastics). The difference is good enough to be PC material, the color is like white teeth; ABS material, the color is slightly pale. Of course, some of the inferior products are made of ordinary plastics and engineering plastics, and the color is white and medium black. There are many low-priced switch ABS materials, and the mid-to-high-end products basically use PC materials. Of course, PC materials are also divided into many grades of prices, and the ingredients of the added materials are also different. High-quality PC material, good flame-retardant performance, impact resistance and no discoloration. Poor quality products are pale in color, coarse in texture, and poor in flame retardancy, which creates a fire hazard for household electricity. Generally good products have a smooth appearance, fine workmanship, no burrs and peaks, and a translucent color.

Take the frame of the switch and pinch it with your hand. The frame can be deformed, but it does not break, which means it is made of PC.

Looking at the reverse side of the switch, although the switch is a large board from the front, some manufacturers often save costs in terms of functional parts and replace them with the functional parts of the small bean switch.

In addition, there should be some electrical performance parameter signs on the functional parts on the reverse side of the switch panel. The plugs and sockets produced by regular manufacturers are marked with the rated voltage, rated current (the converter must be marked with the maximum rated current or power), the symbol of the power source, the name of the manufacturer, the trademark and the 3C mark. Plugs and sockets with grounding poles must have a grounding symbol, and the rated current of multi-position sockets with power cords should be less than the rated current marked on the plug.

Copper: look at the color and weight. When purchasing copper materials, the product must not only have a very reasonable structural design, but also ensure that the copper material has a certain thickness. The easiest way to judge is to try the plugging force with the plug to see if the force is moderate, and then squeeze it with your hands. Whether the socket is really heavy, good switch sockets are generally heavier.

Secondly, check the color of the socket clip. High-quality sockets are made of tin-phosphorus bronze, purple-red, with hard texture and anti-oxidation. Inferior quality products mostly use brass sheets, bright yellow, soft in texture, and easy to oxidize and change color. If the shrapnel of the socket is white in yellow, it means that the copper content is low, and it may even be filled with iron. The identification of the copper-plated iron is very simple. It is the iron that can be attracted by the magnet, and the copper-plated iron is used. Very easy to rust and turn black.

Other insulating materials: burned. Insulating materials are very important for the safety of switch sockets, but it is difficult for ordinary consumers to judge. Of course, it is best to do a combustion test on the core components when buying. If there is no condition, it is a good material in terms of appearance. Generally, the texture is relatively hard, difficult to scratch, the structure is tight after molding, and the weight is heavier. Insulating materials burn: qualified products should not have flames when they leave the outer flame of the fire, they are flame-retardant materials. Inferior products will burn.

Switch contacts: good switch contacts are available in pure silver and silver-lithium alloy. The conductivity of silver is very good, which can fully meet the requirements of this aspect of the contact. However, due to the low melting point of pure silver, problems such as high temperature melting or deformation after repeated use are prone to occur during use. Therefore, the silver-lithium alloy used by some manufacturers, both The good conductivity of silver is guaranteed, and its melting point and hardness are effectively improved. The silver plated copper surface is almost used, and the worst is the general metal. You can take it apart to see whether the contacts of the switch are silver or not.

Look at the screws: Generally speaking, copper screws are the best for functional parts. Copper-plated screws are also good, but if they are directly iron screws, they are almost impossible. It is very simple. Copper is more expensive than iron.

Conductive sheet: usually a conductive sheet made of silver-copper composite material should be used to prevent oxidation caused by arc during opening and closing. The conductive bridge of the high-quality product is made of silver-nickel-copper composite material. The conductivity of the silver material is excellent, which is enough to meet the national standard of 40,000 switches.

Look at the inner and outer packaging: It is said to carefully check whether the product packaging is complete, whether there is a detailed manufacturer or supplier address and telephone number on the outer packaging, indicating that the product packaging must have a clear address and telephone number of the manufacturer, and there should be instructions for use and a certificate of conformity ( Including 3C certification and rated current and voltage), and will make effective commitments to consumers (such as "guarantee 12 years of life", etc.).

Switch feel: In order to ensure reliable contact connection and reduce contact resistance, a good switch generally has a hard spring, so it has a sense of force when switching, while ordinary switches are very soft, and it often happens that the switch handle stops in the middle position. Cause safety hazards.