1. Check whether there is manufacturer's name, address, telephone number, executive standard, trademark on the size package of the bulb, whether the package design and printing are exquisite and beautiful, and know whether the brand of the product is matched with the famous automobile factory.
2. Appearance: visual inspection: the assembly of filament, lamp cap and bubble shell shall be correct and symmetrical; the welding spot shall be smooth and firm, the lamp cap shall be bright and free of scratches; the bubble shell shall be transparent and free of obvious gas lines and bubbles; the filament shall be regular, neat and free from deformation; the wick shall be neat and skew no more than 5 degrees; the adhesive connecting the bubble shell and the lamp cap shall not be exposed and evenly bonded; the steel seal of the lamp cap shall be clearly typed, with trademark and specification, Some products also have the batch number of the certification number.
3. Mechanical strength: use the left and right hands (wearing gloves) to screw the lamp cap and the bubble shell respectively (with force no more than 15N) to know whether the lamp cap and the bubble shell are firmly bonded; lightly touch the bubble shell on the wooden table and gradually use force to judge the thickness and strength of the bubble shell; use the fingernail to press the lamp cap skin and the foot to see whether they are deformed and judge the strength.
4. Photoelectric parameters: conditional instruments can be used to check whether the current, luminous flux and service life of the bulb meet the parameters specified in the relevant standards and judge whether it is qualified or not.
5. When ordinary consumers purchase bulbs, they can buy qualified products after mastering the characteristics of the first three bulbs.
Characteristics of inferior light bulb
1. The packaging design and manufacturing are rough, with unclear mark, no factory name, no address, no phone, no executive standard, etc.
2. The appearance is dirty, the filament is black and twisted, the inner wire is oxidized black or dark red, the lamp head is rusty and lusterless, there are obvious crooked head, shoulder and core, the lamp head has no steel seal, typing or only the specification has no brand.
3. Low mechanical strength, thin and fragile bulb shell, thin lamp cap, collapse of lamp cap foot and skin by pressing nail, exposed or uneven adhesion between lamp cap and bulb shell.
4. Most of the photoelectric parameters are unqualified.
Don't be careless in identifying light bulbs
1. New products that have not been heard of should be thoroughly understood and cannot be purchased easily, such as "vacuum tungsten halogen bulb", which is pure fake.
2. When purchasing, find out the purpose of the bulb, and determine whether it is a car bulb and which part of the car is used. Never be careless.