In City of Mentor v. Kennell (1992), 83 Ohio App.3d 637, 615 N.E.2d 658, this court held: "Ohio Adm.Code 3701-53-04(A) mandates that 'breath testing instruments shall be checked for calibration no less frequently than once every seven days.' Strict compliance with that requirement means that the machine must be calibrated at least every one hundred sixty-eight hours. In view of the strict liability standard of the Code provision prohibiting the operation of a vehicle over specified breath-alcohol limits, there must be compliance with the established regulations on the part of the city." Id. at 640. In Kennel, the Court held that because the defendant had proven the breathalyzer machine was calibrated after the expiration of the 168-hour limit, the results of the BAC test were inadmissible.