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.