TST Helix test

A daily Browne TST Helix test confirms steam penetration through the helix and confirms that air and other non-condensable gases have been removed.

The chemical indicator contained in the capsule shows a distinct color change from yellow to dark blue/purple when exposed to a specific combination of time, temperature and steam. When all air is removed from the sterilization chamber, steam can penetrate the spiral and the indicator shows a uniform color change.

If air or non-condensable gases are present, it will impair the contact between the vapor and the indicator, leading to a non-uniform color change. Clear yellow markings can be seen on the indicator.

The TST Helix has a limited shelf life and must be replaced after 250 indications. Failure to replace the device may result in device failure and dangerously misleading results.