Vaisala HMT360 - Manual (Page 61)

Chapter 5 __________________________________________________ Measuring at Overpressure
VAISALA_______________________________________________________________________ 59
CHAPTER 5
MEASURING AT OVERPRESSURE
This chapter provides you with important information concerning
measurement in conditions with pressure higher than the normal
atmospheric pressure.
The probes HMP364 and HMP368 are designed for humidity
measurement at overpressure. The maximum measurement pressures
depend on the probe as follows:
The accuracy of the dewpoint measurement is affected by pressure in the
measurement chamber. The actual pressure in the sampling cell is required
to be set to the transmitter by using the serial line command PRES (see
section
PRES Setting Ambient Pressure for Calculations on page 56 or by
using the keypad commands, see section Setting the Pressure for
Calculations on page 46 ).
Pressure Regulator Recommended
When sampling pressurized processes exceeding the maximum
measurement pressure of the probe, the pressure in the measurement
chamber must be regulated to the acceptable level or below. It is
recommended to use pressure regulator before the measurement chamber
to prevent remarkable pressure variations.
HMP364: 0 ... 100 bar (10 MPa), for pressurized rooms and
processes, probe is provided with a nut, fitting screw
and sealing washer
HMP368: 0 ... 40 bar (4 MPa), for pressurized pipelines, ball
valve set available