Voltcraft dl 161s sound level data logger voltcraft dl 161s the voltcraft dl 161s sound level data logger measures the sound level in decibels db and meets the requirements of en 61672 1 the unit is a class 2 device for general field investigations such as performance measurements measurements range between the frequencies of 31 5hz to 8khz and sound levels of 30 to 130db two measuring modes two frequency filters and two time schedules can be preselected and used in any situation the m