Vaisala GMP231 - Manual (Page 22)

User's Guide _______________________________________________________________________
20 ___________________________________________________________________ M211501EN-C
CHAPTER 3
INSTALLATION
This chapter provides you with information that is intended to help you
install the GMP231.
Thermal Management
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 will
be 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 CO
2
measurement), or power off the
probe completely. The GMP231 will automatically stop its
measurement cycle if it detects a high temperature, but it is best if the
incubator’s control system set 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 CO
2
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.