The calibrator serves for the simple alignment of sound level measuring devices and for examination of measuring accuracy the calibrator generates a defined sound signal with a switchable sound level of 94 db decibel or 114 db the sine audio frequency is 1 khz microphones with a diameter of 127 mm 05 inches can be inserted in the calibration chamber the specified accuracies are obtained at an atmospheric pressure of 1013 hpa an ambient temperature of 23c and an air humidity of 65rf