Boveda One-Step Hygrometer Calibration Kit - Box of 20

Humidipak's One-Step Calibration Kit is a simple and surefire method to accurately calibrate any digital or analog hygrometer. The One-Step Calibration kit utilizes Humidipak's 75.5% relative humidity standard - widely used and accepted by chemists and lab professionals to determine the accuracy of any hygrometer (also known as the "salt test"). Humidipak's One-Step Calibration kit is used by some of the top museums in the world to calibrate their instruments, including the renowned National Gallery of Art in Washington D.C.