The HD2114P.0 and HD2114P.2, HD2134P.0 and HD2134P.2 are portable micromanometers for pitot tubes. They are used to perform measurements in air conditioning, heating and ventilation systems. They measure the differential pressure measured from a Pitot tube connected to the inputs of the instrument. Based on the differential pressure the instrument calculates the air velocity. There is connection for K type thermocouple which can be used to make real time compensation for the air temperature. The dimensions of the ducts or vents can be entered on the keypad, and with this information the instrument can calculate volumetric flow rates. . The instruments can be used as thermometers and can be employed with any kind of thermo- couple K sensor if a standard miniature connector is used. The HD2114P.2 and HD2134P.2 instruments are dataloggers they can store up to 36000 samples which can be transferred from the handset to PC via the RS232C and USB serial ports. The logging interval, baud rate can be configured by the user, The instrument can also be used to aquire real time measurements to a PC or a printer. The max min average function calculates maximum, minimum and average values according to the user requirements. Other functions include REL - relativemeasurement and HOLD - current value