Breaking the Sound Barrier So, what do you think of when you hear an “ideal gas?” R22, R12 maybe… natural? Take a look at the F-18 above. It's breaking the sound barrier, and that cloud is a shockwave. It has nothing to do with this article, but I think it's pretty darn cool! An ideal […]

Testo 760 Category IV Multimeter I was standing at a booth at the HVAC Excellence Educators conference, and an instructor walks up, grabs a meter, and asks me, “What's the difference between a category 3 and a category 4 meter?” Well, I really wasn't sure, but I knew that the category 4 meter is rated […]

I was talking about dry contacts with one of my techs, and he looked at me like I had three heads—and one of them was on fire. So, I figured it would be good to cover the difference between wet and dry contacts in a tech tip. Basically, “dry” contacts are switches with no shared […]