Czech to English Tech/Engineering Physics Temperature Sensors

Product sheets in the Czech Republic for temperature sensors appear to have a standard phrase as follows: Snímače jsou určeny pro trvalý provoz v prostředí definovaném parametry dle ČSN EN 60721-3-3 se stupněm přísnosti IE 37 a následujících podmínek. I am particularly concerned with "stupněm přísnosti IE 37" and searched through references in Google and other sources and have not found the English equivalent (possibly TMP37, but I am not sure). Yes, I am aware that 37 degrees Celsius is normal body temperature. If you have the whole sentence, it would be fine but all I really need is the term described above.