These are Bowie-Dick test, Leak Test, Temperature and process control test, Quarterly test using thermocouples, Yearly commissioning and recommissioning test using thermocouples, Air detector performance test and Biological indicator test. For all the above tests the sterilizer should be loaded with a test casket or pack containing about 30 freshly laundered and aired towels as for the Bowie-Dick test. The Bowie-Dick and leak rate test are complementary and can be performed simultaneously. The engineer at commissioning, recommissioning and at quarterly and yearly intervals should do thermocouples and air detector performance test. The Bowie-Dick tape test indicates whether there has been even and rapid penetration of steam into the test load at the commencement of sterilizing stage. The leak test indicates whether the evacuated chamber is adequately sealed. Each quarterly, yearly, commissioning and recommissioning test requires temperature measurements to be recorded by separate thermometric equipment, using a minimum of two thermocouples during two separate performance tests, i.e. a small load test and a full load test. The temperature and automatic process control test should be carried out in association with the first test, the observations should be made as described and recorded. It may be necessary to perform the leak rate test without a single pack in the chamber.