Twin jet chemical thinning
Twin jet chemical thinning exerts etching and polishing actions on the specimen surface. The jets produce an higher etching action to the center of the specimen up to perforation. The result is a perforated dimple with thin edge. This technique is mainely used for insulating monophased (certain multiphased) material, especially metals.
CIME Twin jet chemical device: TENUPOL 5 (Struers)