1684-1038-ND SO2 GAS sensor Data format issue

This is the output I am getting from my SO2 sensor.
Am i wrong here somewhere in the calibration:

102219020510, -27524, 28, 51, 53044, 28061, 30002, 00, 00, 15, 57

As per the datasheet second parameter gives a value from the 0:99999 range. So please guide me on this issue.

Would one of you be able to help this customer?


Thank you for your inquiry.

Bottom of page 4 of the datasheet instructs on the zero calibration sequence in clean air:

Have you gone through this process?

“Wake with any character, then type uppercase Z in the terminal window followed by unlock
code 12345/r when prompted.”

Thanks again, let us know if we can be of further assistance.

Hi Kristof_2649,

I have tried all the commands given in the datasheet but did not solve the negative reading issues. 102219020510, -27524, 28, 51, 53044, 28061, 30002, 00, 00, 15, 57

Each time I will get -27524 or -2147483648. So I can’t understand how to retrieve SO2 PPM Value from this output.


Did you power the device, continuously sample it in clean air for at least an hour to ensure it does not go to sleep, and then give it the “Z” calibration command followed by “12345/r” when prompted?


If “zeroed” too soon, then subsequent reads would give negative values, based on the graph above.