Đầu đo đường kính bên trong (Loại gián tiếp)

In some product conditions, where direct type is not a proper choice, the measurement should use indirect contact type. In this type using metric plug gauge, air nozzle hole is set under a leaf with carbide ball on its measuring point. The carbide ball directly contact the product surface. Differ with direct type, air from the nozzle hole is not directly released into the product.