Is there an inexpensive device for detecting leaks from a microwave oven?
Yes. You can get one from a hardware or appliance store for about $5 to $30. ComfortHouse.com sells one on-line at www.comforthouse.com. While I have tended to downplay the leakage issue in the past, I bought a tester and found that the microwave oven in my laboratory actually leaked significantly. I had used it in many class demonstrations, so it had been abused and the door wasn’t properly aligned any more. I retired it. Incidentally, the tester contains only two components: a fast diode and a current meter. It detects microwave in the same way that a crystal radio detects an AM radio broadcast. However, I should note that both the International Microwave Power Institute (IMPI) and the FDA caution against trusting those simple and not particularly accurate meters, and recommend that you take your microwave oven to a service shop for inspection with an FDA certified meter.