Thermocouple cable icon - BS type N. The same colour coding also represents an IEC Type S thermocouple, but apparently the servers can't afford the extra 4KB of space it would take to have that as a separate file. Fab.
en:Image:Image:MC 96.1 N Thermocouple Grade Color Code.svg, en:Thermocouple
en:User:Sagsaw, recoloured by User:Stannered