Greisinger gof 500 surface sensor for solid surfaces greisinger gof 130 p the greisinger gof 500 is a surface sensor with handle that can be used on any solid surface it has 2x nicr ni coil springs in ceramic tube a 1m silicone cable that is terminated with a mini thermocouple din plug p greisinger gof 130 type k surface sensor mini thermocouple plug 65 to 900 deg