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| Thread ID: 34266 | 2003-06-08 11:22:00 | The future of monitors, TFT or Plasma? | rugila (214) | Press F1 |
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| 150980 | 2003-06-09 02:58:00 | Now now Rugila, there's no need to get huffy . I didn't differentiate beta from electron beams in general because quite simply they are not normally referred to as beta until they reach an appropriate acceleration/energy potential, usually around 40-50 keV . Same for alpha, gamma and x-rays, they are differentiated by their energy level in electron volts . If there was any mileage in it, TV/Monitor manufacturers would have released their new "super high definition beta-beam enabled" CRTs years ago . Instead they left it to the VCR manufacturers to hang their hats on . It didn't work for them either . A monitor CRT will not fire beta radiation at levels of acceleration/energy sufficient to cause cellular damage and it is mischievous to suggest that they do . If you do your research thoroughly you will find that information . I actually used a beta radiation test instrument sensitive to 10 keV and since the average monitor has an acceleration potential of up to 22 keV I figure that was sensitive enough . Instrument calibration certificate is current . The average television fires electrons at 16-20 keV, medical x-rays use 200 keV and surprise surprise, beta radiation from radioactive sources is around 3 MeV . That is 150,000 times greater than the energy level imparted by the electron guns in a CRT . A couple of mm of aluminium will stop 3 MeV of beta radiation, so I think that a steel shadow mask or aperture grill plus leaded-glass faceplate around 1-1 . 5 cm thick will easily contain 20 keV, and so it was proven . Both television and computer CRT screens have been exhaustively tested and (harmful) beta radiation is not on the health-effect horizon because the energy levels are insufficient to damage human tissue or genetic material . I don't doubt that you are an expert in your field, but you may be stepping outside that expertise a little here . I am equipped to make accurate measurements of alpha, beta, gamma and x-ray radiation and my equipment found none . I am satisfied with that . I have seen no reports of injury or illness suffered by users of colour television since its inception in the 50's (US), 60's (UK) and 70's (NZ & AUS) . Up until the early 70's colour TVs were capable of generating x-rays at 25-30keV and quite often did, until solid state EHT rectifiers came into common use . The change to solid state rectification plus leaded glass and over-voltage detection effectively eliminated that risk and I have only ever seen one failure that produced x-ray capability . The only x-ray injuries were to service technicians who ignored warnings and regularly fired up sets with their protective covers removed . IMHO it could be seen as unwise to suggest on a public forum for computer users that use of a CRT based monitor will fire electron beams at or into their heads . That can create enormous fear in the minds of persons not equipped with the knowledge or understanding necessary to rationalise or otherwise assess their personal risk . In my professional opinion, the risk is negligible . I'll take a credit note on the consultancy fee thanks, or you can pay me 50% up front via IDG and I'll flag the rest for goodwill . I'm not greedy . :D Cheers Billy 8-{) :| |
Billy T (70) | ||
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