(1) Field of the Invention
This disclosure relates to measuring and regulating properties of contents of a closed environment.
(2) Description of the Related Art
Numerous processes rely upon observation of contents of a closed environment in order to monitor and control the processes. For example, in a laboratory setting, a substance may be heated in a closed container to facilitate a desired chemical reaction or physical change. These closed containers may be heated using a hotplate stirrer, which can mix substances or keep them homogeneous while holding them at a certain temperature. Maintaining the temperature in these substances as they are mixed can be complicated by factors such as inconsistent transfer of heat from the hotplate to the substance as well as fluctuations in room temperature or hotplate power. Users of a hotplate may therefore use an external temperature probe to monitor the temperature of the substance. Some hotplates have temperature probes built into the plate that can measure the temperature of the heating plate surface. However, due to inconsistent thermal contact between the plate and the container, as well as inconsistent heat transfer to the substance inside the container, the built-in temperature probes typically have low accuracy. Other methods for measuring temperature include lowering a temperature probe into the sample, using a support structure external to the container, to directly measure the temperature of the substance. However, ensuring the probe remains in contact with the substance can be difficult, especially as the substance is mixed or agitated. Furthermore, if the container holding the substance needs to be closed during the heating and mixing process, lowering an external probe into the container can compromise the integrity of the process.
Other closed systems can similarly complicate measurement of properties of the system. There is therefore a need for a method to detect properties of a closed system, without compromising the integrity of the system.