| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a lamp life judging device requiring no operation to be made by maintenance operator and capable of executing a lifetime judgement of the lamp accurately at all times. SOLUTION: A lamp life judging device is composed of a switching device having a terminal 9a where a lamp 6a is connected, a terminal 9b supplied with AC power and a terminal 9c, an impedance measuring part 11 to measure the impedance of the lamp 6a when a voltage to such a degree as not causing the lamp 6a to be lighted up when the terminals 9a and 9c are connected together, wherein the impedance measuring part 11 is connected with the terminal 9c, and a lifetime judging part 12 to judge the lifetime of the lamp 6a on the basis of the lamp impedance given by the part 11.</p> |
