| 1.5.2. | The measurement shall be made using optical methods through the transparent envelope, after ageing with the light source supplied by the electronic light source control-gear at test voltage. | a0c0 |
| 1.5.2. | The measurement shall be made using optical methods through the transparent envelope, after ageing with the light source supplied by the electronic light source control-gear at test voltage. | a0c0 |