Vaisala HMT330 - Manual (Page 106)

User's Guide _______________________________________________________________________
104 __________________________________________________________________ M210566EN-K
Pressure Compensation Setting
The pressure has an effect on humidity calculations and accuracy.
Therefore, accurate calculations can be achieved only when the process
pressure is taken into consideration.
Note that conversions from mmHg and inHg are defined at 0°C and for
mmH
2
O and inH
2
O at 4°C.
NOTE Pressure compensation is intended to be used in normal air only. When
measuring in other gases, please contact Vaisala for further information.
Using Display/Keypad
Use display/keypad to set the pressure compensation. To select the
pressure unit using display/keypad, see section Changing Quantities and
Units on page 100.
1. Press any of the arrow buttons to open the Main Menu.
2. Select Measuring
and press the ►arrow button to confirm your
selection.
3.
Select Pressure compensation and press the ►arrow button to
confirm you selection.
4. Press SET and enter the pressure value in the chosen unit by using
the arrow buttons.
5. Press OK and EXIT to return to the basic display.
Using Serial Line
PRES and XPRES
Command XPRES must be used if the value is changed frequently (for
example, by an automatic system that updates the value). Its value is not
retained at reset, and when set to 0; last value set with PRES is used
instead. Use the serial line and do the following:
PRES [aaaa.a]<cr>
XPRES [aaaa.a]<cr>
where
aaaa.a = Absolute process pressure (hPa)
Example:
>pres
Pressure : 1013.00 hPa ?
>pres 2000
Pressure : 2000.00 hPa
>