How does Braun ThermoScan work? Braun ThermoScan measures the infrared heat generated by the eardrum and surrounding tissues. To help avoid inaccurate temperature measurements, the probe tip is warmed to a temperature close to that of the human body. When the Braun ThermoScan is placed in the ear, it continuously monitors the infrared energy. Quick Overview. The Welch Allyn Braun ThermoScan PRO 6000 ear thermometer featuring advanced measurement technology, has the speed and simplicity you need to capture accurate and reliable temperature readings in a comfortable way for patients. Thanks to Braun’s patented pre-warmed tip and ExacTemp ® technology, Braun ThermoScan ® is widely regarded as a benchmark for accuracy and reliability. That’s why most health professionals choose Braun ThermoScan ®. In fact, Braun ThermoScan ® is the number one brand among doctors.