Vaisala PTB330TS - Manual (Page 36)

User's Guide ______________________________________________________________________
34 ___________________________________________________________________M210983EN-A
2. Check that the MI70 indicator is connected to the HMP155, and
turn it on. Set the correct time, date, and environmental settings
(pressure compensation) if prompted.
3. If the measured quantities or units that appear on the MI70
indicator are not the ones you want, change them from the Display
menu:
a. Open the menu by pressing an arrow button, followed by
OPEN.
b. Select the Display menu and press the right arrow button.
c. Select Quantities and units and press the right arrow again.
d. To select a quantity, move on the quantity you want by using
the arrow buttons, and press SELECT. You can select up to
three quantities.
You can change the measurement unit by pressing UNIT, and
hide a selected quantity by pressing HIDE.
e. After completing your selection, press EXIT to return to the
basic display. You may be prompted to check the environment
settings upon exiting; select YES if you want to check the
settings, or NO to exit.
4. If your HMP155 has the chemical purge option, you can manually
start the chemical purge which will dry out the sensor from the
Functions menu.
When the HMP155 starts the purge, it will stop updating the
measurement values to the MI70 indicator for approximately eight
minutes. The measurements will be unchanging until the purge is
done. While the purge is ongoing, an indicator is displayed next to
the battery indicator.
5. Wait for the reading to stabilize; this may take up to 20 minutes.
Make sure that the Stevenson Screen is closed if you are using one.
NOTE Beware of temperature differences when measuring humidity. It is
essential that temperature of the probe and measuring environment is
the same. Even a small difference in temperature between the
environment and the probe causes an error. Temperature differences
may also cause water to condense on the sensor surface.