Allivan Marketing Eco-Celli Mercury Free Barometers Inspired by The Torricelli Barometer

Always wanted a liquid barometer. This one does not use mercury but a red colored fluid. You need to calibrate it for your location using the supplied syringe and tube to remove a bit of fluid until you get the reading matching a close airport. I used an aviation Metars sight, that shows a map with stations and current pressure. You can also use weather underground, just look at the closest stations to you and crunch the numbers, you'll probably see many stations close enough with measurements only .01 differences. After calibrating, the thing is very accurate. The first 14 hours after calibration it tracked the pressure change along with the airports of 0.1 " and I noted at the hundredths along the way, always within 1/100 . A true demonstration how the atmosphere presses against us all, good thing we press back.