The electric spark detector emits DC high-voltage electricity through a high-voltage probe. When the probe passes through a defective coating surface, the instrument will automatically sound and light an alarm. The current electric spark detectors are mostly divided into two types: 15Kv and 30Kv, used to measure coatings of different thicknesses. Most instruments are equipped with rechargeable batteries, making them convenient for use on construction sites and workshops. There are many types of probes, in order to adapt to different working environments and workpieces. The instrument comes with a calculation table that can calculate the pressure applied based on the thickness of the coating. If the voltage is too high, the coating will be broken down, and if the voltage is too low, the specific location of the defect cannot be detected. The probe of this instrument must not come into contact with the human body to avoid personal injury.

Firstly, according to the needs of the enterprise's products, the purpose of selecting instruments is to ensure that the quality of the enterprise's own products is controlled. Therefore, it is important to pay attention to the adaptability of the instruments to the enterprise's products. For example, for furnace testing, the testing time should be as fast as possible, for incoming material inspection, the testing report should be printed, and for finished product inspection, the authority of the instruments should be considered. If non-ferrous metal manufacturers do not need to determine the content of carbon and sulfur elements, they only need to purchase a microcomputer multi-element analyzer and weighing balance, plus all chemical glassware and reagents, and the total price is about 10000 yuan. In terms of instrument quality, price, and service, the main consideration is the service capabilities of instrument suppliers. The quality and performance of domestic mid-range instrument products are generally similar, with slight differences in functionality. The adhesion mechanism of coatings can be broadly divided into two forms: mechanical adhesion and chemical adhesion. Among them, the mechanical adhesion depends on the properties of the coated substrate (roughness, porosity, etc.) and the mechanical strength of the solid coating film; Chemical adhesion refers to the mutual attraction between molecules at the interface between the coating and substrate, which depends on the physical and chemical properties of the coating and substrate. The explanation of the adhesion mechanism of coatings is generally believed to be more practical in terms of chemical adhesion. There are many methods and instruments for measuring the adhesion of coatings. If the purpose of the measurement and the type of "force" to be measured can be preliminarily determined before the measurement, and a reasonable test method and instrument can be selected accordingly, the electric spark detector can facilitate the comparison of various measurement methods and effectively evaluate the adhesion performance of coatings.