Barometric Measurement - TESTO 400 Instruction Manual

Barometric pressure has a yearly average of 1013 mbar above sea level. Depending on the current
weather, this pressure can deviate by approx. ±20 mbar from the annual mean (high pressure and
low pressure area).
Barometric pressure can be measured, saved and documented (on PC or as a printout on site)
using the testo 400 or testo 650 measuring instrument together with the absolute pressure probe
(Part no. 0638.1645).
Connect absolute pressure probe (part no. 0638.1645) to measuring instrument and switch on. The
measuring instrument displays the current absolute pressure measured at your elevation (unit: hPa).
To attain the prevailing barometric pressure calculated above sea level, the following must be
carried out:
1. Enter the elevation in metres above mean sea level in SPECIAL-P
2. Allocate one of the 3 function buttons with the function
BaromP
3. Press function button.
The measuring instrument now displays barometric pressure (unit: hPaB).
To return to absolute pressure measurement, allocate one of the 3 function buttons with
and confirm.
You can adjust the displayed value to a known reference value in PROBE-A
results in a system accuracy of ±1 hPa for barometric pressure measurement in the reference value
range. You can call your local weather station, for example, for the reference value.
Adjustment:
Use probe connection socket 1 for the adjustment!
Switch on instrument and wait until the measurement menu appears.
Press button.
Select "Probe" - "Adjust"
Enter reference value with the help of the arrow buttons.
Confirm with button.
Adjustment is reset via "Probe" - "Reset".

Barometric measurement

BaromP
48
-Metres amsl.
ARAMETER
(= barometric measurement).
DJUST . The adjustment
AbsP