Carbon monoxide (CO) is a colourless, odourless and taste-free gas, but also poisonous. Its sources include the incomplete combustion of substances containing carbon (oil, gas and solid fuels, etc.). This is why it is necessary to regularly check CO emissions at the combustion points of heating systems and surroundings. testo 315-4 Ambient CO measuring instrument – the features State-of-the-art technology, easy to use, robust design: the testo 315-4 CO measuring instrument is your reliable partner for measuring carbon monoxide in the ambient air. You can, for example, detect CO in the ambient air around heating systems. There is also the option to measure humidity and temperature in parallel. You can view the measurement results directly on the digital display. If the individually adjustable limit values are exceeded, the CO measuring instrument emits an optical and acoustic alarm. The cleverly designed CO measuring instrument with lithium polymer battery ensures energy-saving operation: when not in use, it switches off automatically. Further advantages of the CO measuring instrument Depending on your individual practical requirements, you can extend the performance range of the testo 315-4 CO measuring instrument with optional accessories: TopSafe: the water and dirt-repellent protective case protects the ambient CO measuring instrument even in damp, dirty working environments testo fast printer: the fast printer prints out measurement results directly on site – e.g. as documentation for the customer. Measurement results are transmitted from the CO measuring instrument to the handy testo fast printer via the wireless infrared interface Temperature/humidity module: in additional to carbon monoxide, the module also enables you to measure temperature and humidity testo 315-4 CO measuring instrument for ambient measurements, including USB mains unit, cable, calibration protocol. For quick, precise measurement of carbon monoxide in ambient air – in accordance with DIN EN 50543: The testo 315-4 CO measuring instrument is easy to operate, has a robust design and is of durable quality.