Hi Justin, I think the reason why ESD is more of a problem in the winter here in North America is because of using heating indoors, and also because of reducing ventilation. For the most part, unless you have a humidifier or steam heat, the primary humidity source is outdoor air. Here in the Boston area, the outdoor relative humidity has a very flat monthly average (January and February average is 62%, which is the lowest, and September is 72%, which is the highest). Let's say it's steady at 65%. If you take in 65% RH air in the summer and do nothing to condition it, the RH remains 65%. If you use air conditioning, it will remove some water and reduce the absolute humidity but since it also cools the air, it brings the RH back up again. On the other hand, if you take in 0 deg C 65% RH air and heat it to 23 deg C, it will be only at 15% RH. My apartment hovers right around 20% RH during the winter and static is a big problem. The worst ESD problems I ever saw were in a warehouse in Reno (actually Sparks) Nevada in March. It's a high elevation desert environment which gets pretty cold at night but also has very low humidity. By the time the air was taken in and heated inside the building, I think the RH was in the 5% range!!! Some machinery was generating ESD sparks which could be heard 30 meters away. I was sent there to troubleshoot some equipment problems and it turned out that ESD was the culprit. Our equipment had provisions to dissipate ESD but the little chain which was supposed to be the discharge path had broken off on many of the machines. Replacing it with a more flexible conductive rubber strap fixed the problem. Sean On Sun, Mar 10, 2019 at 7:55 PM Justin Richards wrote: > I think the documentation I have had to read and comply with surronding E= SD > must have originated somewhere with similiar conditions to yours. > > I was always at odds with "ESD is more of a hazard in winter". Static > shocks are less of a problem in our winter. I am guessing because it ofte= n > rains and never below freezing and therefore humidity is higher. We also > get very humid periods in summer but less so. > > Justin > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .