The Fotemp1-4 fiber optic thermometer from Optocon is resistant to microwave radiation and highly electromagnetic environments. Various interfaces as well as analog and relay outputs make the device versatile. The associated software enables evaluation on a PC. With a measuring range of -200 to +300 °C, an accuracy of ±0.2 °C and immunity to RFI, EMI and microwave radiation, the thermometer is particularly suitable for environments in which the use of conventional temperature measuring devices is ruled out due to extreme conditions.