Testo 0613 1712 ntc robust air temperature probe testo 0613 1712 the testo 0613 1712 ntc robust air probe is designed for use with many testo products that require an ntc sensor such as models 110 435 etc the probe is designed as a robust but fast reacting probe for measurement of airflow temperature up to 125 deg c at the probe tip testo 0613 1712 ntc robust air temperature probe