Download Vaisala PTU300 User`s guide

Chapter 4 ________________________________________________________________ Operation
where:
7
=
8
=
Decreasing (steadily or unsteadily); atmospheric pressure
now lower than three hours ago
Steady or increasing, then decreasing; or decreasing then
decreasing more rapidly; atmospheric pressure now lower
than three hours ago
Source: The World Meteorological Organization (WMO)
publication Manual on Codes Vol. I.1, International
Codes, Part A - Alphanumerical Codes, 1995 Edition,
WMO - No. 306. Section C, Code Table 0200: a.
Using Serial Line
Pressure 3h trend and tendency reading is also available through serial
line. Key in the lines below:
>form "P=" p "trend=" p3h "tend=" a3h #r#n
OK
>send <cr>
P= 1024.7trend=
0.8tend=1
The last line shows the values.
For more information on the Form command, see the section
Changing Quantities and Units, starting on page 73.
Missing trend
In addition to this the PTU300 series barometers output a code "*"
when the pressure tendency has not yet been calculated that is, less
than three hours have elapsed since the power-up of the barometer.
The absence of the pressure trend is indicated in a similar manner, too.
NOTE
When the P3H tendency is chosen as a display quantity, the PTU300
logs actual measured pressure, instead of trend or tendency value.
VAISALA _______________________________________________________________________ 57