Boveda One-Step Hygrometer Calibration Kit - 75% RH

Boveda's One-Step Calibration Kit is a simple and accurate way to calibrate any digital or analog hygrometer. The One-Step Calibration Kit utilizes Boveda's 75% relative humidity standard, which is widely used and accepted by chemists and lab professionals to determine the accuracy of any hygrometer (also known as the "salt test"). The 75%Rh pack that comes with this kit uses salt used that is more accurate than the 72% or 69% packs. All Boveda packs are +/-1.0% accurate, while the 75%RH is +/-0.03% accurate! Simply place your hygrometer inside the bag, close the zipper, and wait 24 hours. A perfectly-calibrated hygrometer will read 75%. If your hygrometer reads above or below that number, adjust the calibration by the number of percentage points it is off from 75%. Then place the hygrometer back in the bag to check that the adjustment worked. The reason to use t he included Boveda calibration bag and not a traditional ziploc bag is that it is thick enough and has a special glass coating to stop the moisture exchange. This ensures you are accurately testing the relative humidity inside the bag.   Features Easy to use. Completely maintenance free - no activation required. Lasts approximately 1-year after opening, with a 4-year shelf life before opening. Produces an environment of 75-percent humidity Boveda 75%RH packs are +/-0.03% accurate Boveda calibration bag is very thick and has a special glass coating to stop the moisture exchange with outside air Dimensions Exterior Bag Dimensions: 5.5" x 7" Interior Bag Dimensions: 4" x 4.5"