Chapter 2 __________________________________________________________ Product Overview  
VAISALA_______________________________________________________________________ 15 
Table 2  Quantities Measured by PTB330   
Quantity Abbreviation 
Pressure (measures average 
pressure from P
1
, P
2
, and P
3
) 
P 
Pressure from barometer 
module 1 or 2 or 3 
P
1
, P
2
, and P
3
 
Temperature of barometer 
module 1 or 2 or 3 
T
P1
, T
P2
, and T
P3
 
Pressure trend (includes 
pressure tendency on display) 
P
3h
 
Pressure difference (P
1 
-P
2
)   ΔP
12
 
Pressure difference (P
1 
-P
3
)   ΔP
13
 
Pressure difference (P
2
-P
3
)   ΔP
23
 (available on serial port 
only) 
QNH pressure  QNH 
QFE pressure  QFE 
Height Corrected Pressure   HCP 
Pressure tendency (available on 
serial port only) 
A
3h
 
 
Outer Structure of the Barometer 
 
Figure 1  Barometer Body 
Numbers refer to Figure 1 above: 
1  =  Cable for signal/powering Ø 8 ... 11 mm 
2 = Pressure port 
3  =  Cable for optional power supply/relay module Ø 8 ... 11 mm 
4 = Cover LED 
5  =  Display with keypad (optional) 
6  =  Cover screw (4 pcs)