I want to measure SO2 in the air and I plan to use the 110-601 from Spec sensor. However the documentation of the sensor is quite sparse, so I'm hoping someone here with some more experience could help me out.
The sensor has '4' pins, but I'm not quite sure what they do. I assume the Reference pin serves as the Vin and the Counter pin is the thing you read to get the measured ppm. But what do the two 'working' pins do?
There exists a library for the more expensive ULPSM version, is this library also usable for the 110-601?
The naked sensor won't do you any good. You will need one mounted on a PCB, together with an interface. Unless you are skilled in op amp circuit design ...
const int C1 = A0;
const int T1 = A3;
//averaging times, keep these low, so that the ADC read does not overflow 32 bits. For example n = 5 reads ADC 4465 times which could add to 22bit number.
const int n = 5; //number of seconds to read gas sensor
const int m = 1; //number of seconds to read temperature sensor
const int s = 10; //number of seconds to read all sensors should be greater than n+m+1
const float Sf1 = 11.61; //nA/ppm change this to match your barcode!!!!
unsigned long etime;
SO2 sensor1(C1, T1, Sf1); //Sensor Types are EtoH, H2S, CO, IAQ, SO2, NO2, RESP, O3, and SPEC (custom)
While there is some useful information there it focuses mostly on the ULPSM, which is the more expensive variant.
For anybody coming across this thread in the future: Here is a tutorial on a different spec sensor sensor with very similar features, I haven't tested this yet but it looks like it would also work for the 110-601.