Vaisala PTU300 - Manual (Page 23)

Chapter 2 ___________________________________________________________ Product Overview
VAISALA ________________________________________________________________________ 21
CHAPTER 2
PRODUCT OVERVIEW
This chapter introduces the features, advantages, and the product
nomenclature of the Vaisala Combined Pressure, Humidity, and
Temperature Transmitter PTU300.
Introduction to PTU300
The PTU300 transmitter provides reliable pressure measurement in a
wide range of applications. PTU300 series transmitters use a
BAROCAP® silicon capacitive absolute sensor developed by Vaisala for
barometric pressure measurement applications. The measurement
principle of the PTU300 series digital transmitters is based on an
advanced RC oscillator and three reference capacitors against which the
capacitive pressure sensor is continuously measured. The microprocessor
of the transmitter performs compensation for pressure linearity and
temperature dependence.
The applications of the PTU300 range from calibration laboratory
environmental condition monitoring to laser interferometer active
wavelength compensation and GPS meterorological measurements.
The PTU300 transmitter combines three measurement parameters:
pressure, temperature and humidity. The quantities measured and
calculated by PTU300 are presented in Table 4 on page 22. The
quantities available as an option are presented in Table 5 on page 22.
Analog outputs can be chosen between current and voltage signals.
Alternatively, digital outputs RS-232 (standard) or RS-422/485 (optional)
can be selected. A local display is also available.
The PTU300 transmitter is available with one or two pressure
transducers. The PTU301, PTU303 and PTU307 probes are available for
the PTU300 transmitter. A PTU30T model with only the temperature
probe (no humidity measurement) is also available.
In outdoor applications it is recommended to use the HMT330MIK
mounting kit with the PTU300 transmitters.