It will measure the concentration of CO between 1-999 PPM (parts per million) with a resolution of 1 PPM and factors in a small zero float. Typical battery life of this monitor is 500 hours when used with an alkaline battery. This device can be used by professional technicians and experts to detect CO build up in industrial and residential environments. It is able to detect CO in living areas, garage and around gas burner appliances. The detector will only indicate the presence of carbon monoxid