At 01:19 PM 9/1/2010, Walter Banks wrote: >How is the outdoor UV getting to the sensor? The sensor is mounted horizontally (inside the flame head) looking=20 straight out at the spark gap. Nothing blocks the sensor from seeing=20 past the gap, which is open sky in this setup. We tried shielding the sensor - I had them install a tube from the=20 face of the sensor to about 3/4" away from the spark gap as well as=20 mounting an aluminum shield on the other side of the spark gap (to=20 minimize how much sky the sensor sees. Both of these items were=20 fashioned from standard theatrical lighting blocking foil - this is a=20 very heavy-gauge aluminum foil colored flat black. However, this=20 didn't appear to help. >I would be willing to bet that the outdoor UV is basically a >DC component on the UV sensor and it might be eliminated >with a simple filter in the system either analog or digital >implemented in one of the 8pin processors. That might be the case but I haven't gone there yet - this sensor is=20 part of a UL / CSA listed flame protection controller and I can't=20 modify any part of that unit without destroying its certification. Thanks for the suggestions! dwayne --=20 Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .