摘要 |
In a method for determining whether electronic charge has been accumulated on the inner surface of a cathode ray tube (10), at least one electron beam is generated within the cathode ray tube and is deflected so that it hits the inner surface of the funnel (14) of the cathode ray tube. The temperature of a portion of the cathode ray tube is measured and is compared with a reference temperature value. If the measured temperature is greater than or equal to the reference temperature, it is determined that the electronic charge has accumulated. If the measured temperature is below the reference temperature, then the electron beam or beams have become switched off and electronic charge may not have accumulated on the inner surface of the cathode ray tube.
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