Some articles on alcotest:

Center For Policy And Research - Reports - Breathalyzers
... that the contract governing the use of the breathalyzer, the Alcotest, forbids the State from providing its breathalyzers for independent scientific testing ... In addition, the manufacturer of the Alcotest prohibits any entity other than the State to purchase the Alcotest, even for independent scientific testing ... The report argues that the combination of prohibitions immunizes the Alcotest from challenge, and effectively prevents scientists and defense counsel from determining its ...