Fixed Temperature Probe – Overview Temperature measurement is important wherever temperature-sensitive products are studied, produced, stored or transported. A PT100 sensor changes its electrical resistance with temperature. Its resistance value is 100 ohms at 0 ⁰C. This characteristic is used in a bridge circuit to generate a signal suitable for further processing. Fixed Temperature Probe – Features Class A sensors with a 4-wire connection> Connection: 4-pin Binder connector plug series 711 90: Response time to reach 90 % of actual temperature change (air/water) with an air flow velocity of 2 m/s.