Bowie & Dick Test Pack is single-use device that consist of a lead-free chemical indicator, BD test sheet, placed between porous sheets of paper, wrapped with crepe paper, with a steam indicator label on the top pf the package. It is used to test the air removal and steam penetration performance in pulse vacuum steam sterilizer. When air is discharged completely, the temperature reaches to 132℃ to 134℃, and keep it for 3.5 to 4.0 minutes, the color of the B-D picture in the pack will change from pale yellow to homogeneous puce or black. If there is air mass existing in the pack, the temperature cannot reach to the above requirement or the sterilizer has leakage, the thermo-sensitive dye will keep primary pale yellow or its color changes un-evenly.