The Vaisala PTU300 series is a versatile, multi-purpose instrument that combines pressure, humidity and temperature transmitters into a single unit. Each model of the PTU300 series includes the base station and a probe especially designed to suit specific applications. The PTU301 is ideal for laboratories, the PTU303 for outdoor use, the warmed PTU307 probe for demanding meteorology, and PTU30T for pressure and temperature measurements only.

The PTU300 transmitter uses sensors known for their high accuracy and excellent long-term stability: the Vaisala BAROCAP® is used for pressure measurement and the Vaisala HUMICAP® for humidity measurement. The temperature sensor is a platinum RTD sensor. Two classes of accuracy are available for barometric pressure reading and two barometric pressure sensors are available for added reliability.

The PTU300 series features a large numerical and graphical display allowing users to easily monitor operational data, measurement trends and 1-year measurement history. The optional data logger with real-time clock makes it possible to generate over four years of measured history, and zoom in on any desired time or time frame. The battery backup of the real-time clock guarantees a reliable logging of measured data. The display alarm allows tracking of any measured parameter, with a freely configurable low and high limit. The PTU300 comes with a standard RS-232 serial interface. The output format is compatible with major GPS receivers and NMEA coded messages. RS-485 is available as an option.

The recorded measurement data can be viewed on the display or transferred to a PC with Microsoft Windows® software. The transmitter can also be connected to a network with an optional LAN interface Ethernet connection. A USB-RJ45 cable makes it easy to connect the service port of the PTU300 to a PC. PTU300 is also capable in applying the MODBUS communication protocol and together with an appropriate connection option provides either MODBUS RTU (RS485) or MODBUS TCP/IP (Ethernet) communication.