Testo 317-3 CO Monitor 

The testo 317-3 CO monitor detects the presence of carbon monoxide in the surrounding area and warns the user both visually and audibly about dangerous gas concentrations e.g. when installing and servicing gas heaters.
3 year warranty on CO sensor
Visual and audible alarm
No zero phase, instrument can be used immediately
Adjustable alarm threshold
CO zeroing at site
Self-test function
 
Probe - CO
Meas. Range
  0 to +1999, ppm
Accuracy
  �3 ppm (0 to +29 ppm)
  �10 ppm (0 to +99 ppm)
  �10 % (+100 to +1999 ppm)
Resolution
  1 ppm
 
 
Incl. carrying case with belt clip, headphones, wrist strap, sampler and calibration protocol