The American Standard – UL2034
This standard was implemented in the early nineties to cover products being supplied and used in the American (and North American) markets. It has also been subject to a number of amendments over the years (1997,1998, 2001).
Products officially approved to this standard must be clearly marked with the UL symbol (perhaps add picture of UL symbol to web page).
Main alarm requirements :
- at 30ppm CO, the alarm must not activate for at least 8 hours
- at 70ppm CO, the alarm must not activate before 60 minutes but must
activate before 240 minutes
- at 150ppm CO, the alarm must not activate before 10 minutes but must
activate before 50 minutes
- at 400ppm CO, the alarm must not activate before 4 minutes but must activate before 15 minutes