We are using the zmod4410 for tvoc sensing but it says it is sensitive to hydrogen. Could we calculate an H2 level from the readout? Not sure if anyone is using it that way.
Hello,
Thanks for reaching out Renesas Engineering Community.
As you already know ZMOD4410 is a MOX sensor and it reports a raw resistance value (RMOX) for the gases.
Regarding your request, please let me inform you that the ZMOD is not calibrated towards Hydrogen (H2) and it will not give a ppm reading.
The IAQ 2nd Gen operation mode will give excellent sensitivity to Hydrogen, however we do not offer a calibration function and we recommend to customers to do their own calibration. We recommend to use the RMOX[6] value reported from the algorithm for the IAQ 2nd Gen Mode.
Here you can find the precompiled libraries we give for the IAQ 2nd Gen mode:
ZMOD4410 - IAQ and TVOC Firmware - 2nd generation algorithms (IAQ 2nd Gen) - recommended for new designs
The function between the H2 concentration and the resistance value is a double logarithmic function:
It is log(RMOX[6]) versus log(H2 concetration in ppm) which a linear curve as you can also see from the screenshot below:
Hope it helps.
Best Regards,
IK