|
|
 |
|
|
|
|
| pho·to·tube [ fṓtō tb ] (plural pho·to·tubes) |
noun |
|
| Definition: |
| |
photosensitive device to control electric current: an electron tube that uses a cathode to convert visible light into electrical current at a rate proportional to the intensity of the illumination
|
|
|
|
