GMP231 is designed to remain installed during typical heat sterilization cycles that raise the chamber temperature to 180 °C (356 °F). Since 180 °C is the target temperature for sterilization, it is likely that there are hotspots inside the chamber that are above this temperature. Avoid installing the GMP231 near such hotspots, for example near heating elements. Do not expose the GMP231 to temperatures higher than 195 °C / 383 °F.
The following considerations are most important for achieving the specified heat durability and measurement stability:
- Only the sensor and its filter should be exposed to heat. The filter must be completely in the heated chamber. The probe body must remain inside the unheated chamber wall so that only the end of the probe body extends exactly 2.5 mm into the chamber.
- During the sterilization cycle, you must set the GMP231 to standby mode (turns off the CO2 measurement), or power off the probe completely. The GMP231 automatically stops its measurement cycle if it detects a high temperature, but it is best if the incubator’s control system sets the GMP231 to standby mode when the sterilization cycle is started.
- The installation tube must be sealed from the chamber side to limit heat conduction, and to prevent CO2 in the chamber from entering the probe. Vaisala recommends a 44 mm diameter installation tube together with Vaisala’s silicone plug.
- If the chamber wall contains heating elements, or has a construction where hot air is circulated inside the wall, design the installation tube so that excessive heat is not conducted to the GMP231.