Emissivity
| Material | Temp | Ratio of emissivity |
| Black body radiation / schwarzer Koerper | 20 | 1 |
| Aluminium | 20 | 0.08 |
| Aluminium , polished / poliert | 20 | 0.04 |
| Glass | 20 | 0.93 |
| Cast iron without cinder / Gußeisen o. Zunder | 20 | 0.42 |
| Copper polished / Kupfer poliert | 20 | 0.045 |
| CuZn polished / poliert | 20 | 0.05 |
| Oil / Oel | 20 | 0.82 |
| Procelain / Prozellan | 20 | 0.92 |
| Steel polished / Stahl poliert | 20 | 0.28 |
| Steel plate zinc coated / verzinktes Stahlblech | 20 | 0.23 |
| Steel plate tin coated / verzinktes Stahlblech | 20 | 0.07 |
| Roofing paper / Dachpappe | 20 | 0.91 |