One of the most common calls WPI Customer Support receives relates to Audiometric Daily Calibration failures. 90% of the time the culprit is a weak battery. We recommend changing the Alkaline battery at least once a month if you test frequently. If testing is infrequent, then always start with a fresh battery for your daily calibrations. Remember, nothing makes a Calibrator happier than a FULL Battery!
Please Recycle used Batteries.