Don, The manufacturer defines the acceptable level of degradation. It must be consistent through out all the reports on your products. When I test my products I specify that the image must be 'clearly discernable' (i.e. if you can see the image of a person, but you can't easily tell whether it's a man or woman - that is NOT clearly discernable). However, this is indeed a subjective criteria and open to interpretation.
John Juhasz Fiber Options -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: Tuesday, May 16, 2000 8:46 AM To: [email protected] Subject: Alarm Systems Compliance Hello Friends, We are testing a CCTV system to the alarm systems standard EN50130-4. The standard identifies the usual immunity requirements with different levels. The interesting situation is that degradation of the video as viewed on the monitor is allowed for conducted immunity and radiated immunity for 10V and 3V, but degradation is not mentioned for other immunity tests. EFT is specified at different stress levels also, but degradation is not addressed. The requirement is that there is no change in status. Status is determined by observing the monitors. The switcher did not change cameras nor did it change monitors ( i.e., camera "A" is still linked to monitor "A" and "B" to "B", etc.). As no change in linking has occurred (no apparent change of status), and visual degradation is not specified, does slight "sparkles" observed on the monitor screen due to EFT indicate a compliant or non-compliant result? If the answer is "it depends on how much degradation", how does one "measure" the point at which the product crosses over from "allowed" degradation to non-compliant degradation? At one end of the spectrum one can clearly see the intended image; at the other end of the spectrum, the screen is so obliterated with "sparkles" that the image is indeterminate. What defines the cross-over point? How does one establish a repeatable, non-subjective criteria? Or is that beyond the intent of this standard? Your interpretations are appreciated. Don Umbdenstock Sensormatic ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: [email protected] Michael Garretson: [email protected] For policy questions, send mail to: Richard Nute: [email protected]
