the cast iron surface plates should be installed in the airiness dry environment and away from heat sources, corrosive gas and liquid. The surface plates are checked regularly following national standard. Re-testing period is 6 to 24 months in accordance with specific conditions. Conditional factory can keep constant temperature in order to keep precision grade of surface plates.

The inspection surface plats are basic datum for precision inspection in production department or measure department; the lineation surface plates are used for basic datum of lineation and marking.

Many factors, for example, temperature, humidity, vibration, etc., will affect the flatness precision of the cast iron surface plates in some extent, so it¡¯s very important to control the environmental aspects. But in order to get the higher precision in the daily using, you should pay more attention to the maintenance and proper use. The improper use will lead to an error measuring result. The insufficient maintenance will lower the surface precision. Even worse, the quality of the inspected products will be affected accordingly. Thus, we need to follow the below items when using and maintaining the cast iron surface plates.

There are five identification items together about the surface plates: the appearance and surface quality, roughness of working surface and sides, included angle of sides, contact point of scraping surface plates and the flatness of working surface.

The disadvantages are not withstanding impact and beating, high humidity brings about granite deformation, and the hygroscopicity is 1%.