Guidelines

The PDA Technical Report No. 3 offers useful guidelines for the qualification of Dry Heat Sterilization processes.

The usual number and positioning of measuring points varies depending on the technique used. In a dynamic technique, temperature sensors are placed in three horizontal lines through all the load; one line at the beginning, one in the middle and the last one at the end of the batch. The number of sensors per line depends on the width of the tunnel, but five sensors are commonly used as a rule of thumb. In a static technique, temperature sensors are placed in different levels of each crate and the number of points can be as high as one five per crate.