I ordered 3 digital altimeters for use with my 6 science classes. We launched on 80-90 degree days in 100% humidity (May in Charleston, SC). They worked exactly as specified in the directions. The only problem is they are easily lost. We lost 1 when the clip failed and it separated from the rocket and got lost in a grassy field. We lost 2 when our rockets broke up and landed on the school roof. Even searching the roof, we were unable to recover the altimeters. It would be helpful if they came with a GPS locater or a beeping sound! They are a too pricey to be shrugged off as disposable.
