I have a NDIR with voltage output of 0.8 - 4 VDC and the CO2 measurement is from 0 - 2000 ppm. From previous posting, the voltage output range is quite good, that is from 0 - 4 DC,1-5 DC and not fraction as above etc. Then there is a function map(). Which is better to use function map() or to calculate. Thank you in advance for any advice.