Convert pressure from PPM to Pascals
ppm2pa(ppm, P)
Pressure value in umol/mol of class units
Atmospheric pressure value in kPa of class units
Value in Pa of class units
$$\mathrm{Press}(kPa) = \mathrm{Press}(ppm) P(kPa)$$ $$\mathrm{Press}(Pa) = 1000 \mathrm{Press}(kPa)$$