Spectronic Epitrend consist of physical sensor devices installed in the public environment. The devices perform anonymous measurements of facial temperatures of passers by. Based on these measurements, temperature histograms are generated and sent to this web portal every hour. No other data is sent from the devices at any time.

A temperature histogram is a completely anonymous dataset, consisting only of information on how many measurements points were found within certain temperature intervals. In the event that too few measurement points were collected during a single hour, the results will be aggregated across several hours in order to assure that no individual can ever be singled out from the data provided by the device.

The Spectronic Epitrend is specifically designed, with regard to both hardware and software, to assure that it can not be misused by anyone in order to identify or track any single individual.

When performing facial temperature measurements it is of importance to understand that deviating temperatures may occur for a variety of reasons. What is of importance is therefore the overall conclusions that can be drawn from analyzing large volumes of measurement values. It is also of importance to be aware that facial temperature measurements are typically somewhat lower (around 0.4°C) than temperature measurements performed in a body cavity.