Vaisala PTB220 - Manual (Page 47)

C HAPTER 5_______________________________________________________________ INSTALLATION
V AISALA _________________________________________________________________________ 41
The PTB220 series digital barometers comply with the CE norms for
electromagnetic compatibility provided that braided cable and proper
grounding techniques are used. The use of an unbraided cable may
result in digital communication problems and erraneous
measurements.
Pressure connections
The barometer is equipped with a barbed pressure fitting which is
ideal for 1/8" internal diameter tubing.
If some other pressure fitting need to be used, it is possible to replace
the standard barbed fitting. The main pressure connector in the
barometer housing has a metric M5 internal thread. It is, however, in
practice possible to use pressure fittings with a non-metric 10-32
external thread together with this main pressure connector.
Note that the barbed pressure fitting cannot be used in turbulent or
high-speed static wind conditions. The barometric pressure
measurement accuracy quoted for the PTB220 series digital
barometers does not include any wind or air conditioning system
induced measurement errors. The pressure fitting must also be
protected from rain as water may get into the pressure connector and
cause errors in the pressure measurement.
The PTB220 barometers are designed to measure the pressure of
clean, non-condensing, non-conducting and non-corrosive gases only.