Testo 317-3 - CO Monitor Incl. carrying case with belt clip, headphones, wrist strap, sampler and calibration protocol 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 Operating temperature = -5 to +45°C Battery type = 2 batteries Type AAA Battery life = 150 h 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