It says range from 10-1000 ppm CO. I need the accuracy in the near zero ppm range. Have you used that sensor? Is it able to detect will from 0-10 ppm? For what I'd be doing with it I would fire an alert at 5 ppm and an alarm at either 10 ppm or 15 ppm.
Edit: The other issue is the sensitivity to CH4. I can't find any information on hydrogen gas sensitivity either.