In the context of the CORA project, the measurement instrumentation and detectability of heat transitions separately for convection and radiation of small surface areas was examined. In preliminary tests the expected heat flows were detected. On this basis, a miniature sensor was developed.
Here the heat transfer was determined by commercial Peltier modules and additionally the exact ambient temperature by means of a PT100 sensor. The sensor signals were evaluated through control electronics which will be developed in parallel – which are interfacing with the PC besides. Over a PC program necessary calibration procedure and the transfer of measurement data can be accomplished.
A small surface sensor, which measures energy transport through a surface element, can be utilised in a variety of possible fields of application. For example, by arranging several sensors in a matrix shape, hotspots can be identified and if necessary, eliminated by making constructional modifications. In this way, it is possible to use larger areas for the cooling of components and to purely passively dissipate the resulting heat.
A particular advantage arises from the bi-directional properties of the sensor, not only can the heat dissipation at a particular point be measured, but also the heat absorption from the environment.
In the context of the CORA project, measurement instrumentation and detectability of heat transitions separately for convection and radiation of small surface areas was examined. On this basis a miniature sensor was developed. The heat transfer is determined by commercial Peltier modules and additionally the exact surface temperature is detected with an integrated thermocouple.
The complete sensor element consists of two heat flux sensors. One sensor element is blackened to approach the emission behaviour of a black body. This sensor is cooled both by convection and radiation. Via a second sensor with a mirrored surface a pure convection can be determined. This surface was gold plated with 24Kt to get a good resistance against environmental influences in addition to high reflection.
The sensor signals are evaluated through a Keithley K2000DMM with a 10-channel scanner card. Its measurement procedures are controlled through a PC program with graphical user interface and the transfer of measurement data to a PC hard disk archive can be accomplished. Additionally, a data export in CSV format is possible to visualize measurement data.