| Year | 1950 |
| Date | 12-Jan |
| Volume | 102 |
| Issue | 2,538 |
| Page | 58 |
| Category | Electrical |
| Part | |
| Title | A 500-Volt Insulation Tester. From Government Surplus |
| Author | Stuart H.Rutherford |
| Notes | The generator, two views of the assembled instrument, circuit of ratiometer as used in aircraft, circuit of insulation tested, details of gearbox, calibration, the finished article |