Question: How often do breathalyzers have to be calibrated in California for DUI?

Answer: For DUI in California, Generally every 10 days of 150 tests, whichever comes first. Check with title 17 about the rules and regulations regarding breath machines. I would recommend hiring an attorney to handle your case as Court Procedure and particularly DUI defense is very technical.
Phil Hache,
Criminal Defense & DUI Attorney
Handling DUI and Criminal matters throughout Courts in Southern California including Van Nuys, CA, San Fernando, CA, Burbank, CA Glendale, CA Pasadena, CA Metropolitan Court, Bellflower, CA, Alhambra, CA, Malibu, CA, Compton, CA, Santa Clarita, CA, Airport Court, Chatsworth, CA Inglewood, CA, Los Angeles, CA and other Courts