State v. Busch
In State v. Busch, 217 Wis. 2d 429, 576 N.W.2d 904 (1998), the supreme court concluded that an Intoxilyzer 5000 was entitled to a presumption of accuracy and reliability if the instrument retained its analytical process, despite alterations made to the machine following its initial certification. See Busch, 217 Wis. 2d at 435.
Because software changes to the machine did not change the analytical processing, the court concluded that the instrument was entitled to a presumption of accuracy and reliability. See 217 Wis. 2d at 438.