Vaisala PTB210 (analog) - Manual (Page 17)

Chapter 4 ___________________________________________________ Calibration and Adjustment
VAISALA________________________________________________________________________ 15
3. Give reference pressure values and the corresponding corrections.
Calculate the corrections according to the equations below.
NOTE Because the lower end of voltage output is not exactly 0 V, use as
lower calibration point a value approximately 40 mV above the lower
end limit. Thus with scale 600…1060 hPa and 0…5V output the
lowest calibration point will be 604 hPa.
max
min max
min
) ( *
out
out
measured U
P P U
P P
−
+ = (1)
previous measured reference new
corr P P corr + − = ) ( (2)
Example to calculate the higher end correction:
Barometer scale 600…1060 hPa with the 0…5V output.
- Output reading 4.8887 V
- P
measured
= 600 + [4.8887 * (1060-600)]/5 = 1049.76 hPa
- Reference value 1050 hPa
- Previous correction 0.22 hPa
New correction (1050 - 1049.76) + 0.22 = 0.46 hPa
NOTE The previous corrections have to be added to the new ones (see the
example above).
The correction at the lower end is calculated in similar way. The new
calibration date can also be given.
The values are given in hPa: the reference value as whole number, and
the correction with two decimals.