Testo 0560 5522 552 digital vacuum gauge with bluetooth testo 0560 5522 p the testo 552 is a digital vacuum measuring instrument ideal for use during the evacuation of refrigeration systems and heat pumps it measures even the smallest absolute pressures and provides highly precise information on the status of the dehumidification of a system its robust construction makes it suitable for daily use and protects it from dirt and water p p this new version of the testo 552 connects via bl