Monitoring Steam Saturation & Penetration

4DIR Sensor is the first of a new range of devices from Steelco, allowing the monitoring of the sterilization process to a new dimension: together with time, temperature and pressure, steam saturation is also the 4th parameter that is critical to monitor in the sterilization process. The Sensor works by measuring steam saturation. Steam presence and steam penetration are proven, surveyed, and registered in real-time during the sterilization plateau every single second together. Every sterilization cycle being a unique event, continuously monitoring steam penetration throughout each process provides enormous safety and consistency benefits.


How Does It Work?

It measures steam saturation, the only parameter that can guarantee that sufficient steam is present in the sterilizer chamber and load and that there are no excessive residues of non-condensable gasses. The measurement takes place at the close end of a long narrow channel (70 cm) in the chamber to simulate a worst-case scenario of the most challenging hollow surgical instruments. The steam filters an emitted infrared radiation according to its concentration level: the greater the absorption of IR light by steam, the higher the steam saturation.

Additional Benefits

“Self-Testing” Device

A self-diagnosis before each steam penetration test cycle is yet another unique feature not available in other digital devices or chemical or biological indicators.


Steam penetration traceability by automatically recording data without any manual intervention, reducing handling times and avoiding potential human error, and dramatically enhancing the security of the whole process.


Digital tests, consistency, and improved process efficiency guarantee savings in a short time.

Practical Guide

A practical guide is available; including:

  • Questions and Answers to quickly get into the topic of how the 4DIR sensor technology can improve your sterilization process safety.
  • Scientific literature and additional comments.
  • Deep dives on related topics.
Download our 4D Sensor Guide