It is often desirable to measure certain industrial process parameters such as temperature, pressure or the state of a process reaction in order to optimize the process. For example, laminated composite layups may be placed in an autoclave in order to compact and cure the layup at elevated temperatures and pressures. It is sometimes desirable to measure the pressure that is applied at various locations over the layup since these local pressures may have an affect on the porosity, and thus the quality, of the cured composite part.
Collecting process data of the type mentioned above is more difficult where the process is carried out under hostile environmental conditions, such as at elevated temperature and pressure levels commonly used in autoclaves, due to the sensitivity of the electronic measuring devices to elevated temperature and pressure. Currently, in order to measure parameters such as the pressure applied to a layup, and temperature, pressure sensors and thermocouples placed on or near the layup are connected by long lines that must be placed and carefully arranged inside the autoclave. In the case of vacuum or pressure sensing, a relatively cumbersome, heavy hose must be used to connect the layup with a junction box on the autoclave wall. These lines and hoses must be individually connected to fittings in the junction box in order to couple the measuring devices to electronic data collection equipment outside of the autoclave. Coupling the measuring devices to data logging equipment located outside of the autoclave requires multiple wiring penetrations through the autoclave wall.
The procedure described above has a number of disadvantages, including the time and labor needed to plan, arrange, orient and hookup the lines and hoses inside the autoclave. The wires and hoses are relatively costly, and provide little or no flexibility in design layout. Moreover, the measurement sensors cannot provide useful data until they are hooked up to the autoclave, thus precluding the possibility of making preliminary measurements before the layup is loaded into the autoclave. Similarly, the measurement sensors cannot provide useful data after they are unhooked and the layup has been removed from the autoclave to undergo cooling.
Accordingly, there is a need for a system for measuring and transmitting process data from inside an autoclave that is economical, easy to setup and eliminates cumbersome connecting wires and hoses. Further, there is a need for a system of the type mentioned above that is highly flexible and allows measurement of at least some parameters before a part layup is loaded into the autoclave and/or after the part layup has been removed from the autoclave.