A calibrating device (1) for a breath alcohol measuring device (25) as well as a system including such a calibrating device (1) and a breath alcohol measuring device (25) are shown and described. A test gas container (3), which provides a test gas, which can flow via an outlet (5) into an inlet (11) of a measuring adapter (9), is provided in the calibrating device (1). A measuring adapter (9) forms a flow path (17), in which the test gas is subjected to a dynamic pressure. The measuring adapter (9) is configured for being connected to a breath alcohol measuring device (25), which triggers a measurement when the dynamic pressure of the test gas reaches a pressure threshold value of the breath alcohol measuring device (25).