1. Preprocessing : Clean up oils and fats, paincoating, rust, furscale, dirt etc. which prevent cleaning solution to penetrate.
2. Penetration : Applying one of each of immersing, spraying and brushing according to quantity,dimensions, shape and quality of material of part, the area to be inspected must be covered by penetrating splution untill the time necessary for penetration has been finished.
3. Cleaning : Only removing penetrating solution attached on the surface of inspecting part, wipe off with rags at first, then wipe off completely with rags on which touch of penetrating splution is put on.
4. Dvelopment : This is the way by making use of capillary phenomenon to reveal magnified indication of flaw by sucking out penetrating solution which penetrates into flaws.
Dveloping solution has to be shaken before use and put on thinly and evenly.
5. After treatment : Developing solution can be get rid of by cleaning solution. Parts which are in danger of getting rust have to be done anti-rust treatment immediately.