Gas sensor- Mics 4514

[Dhiraj Gehlot]

Hello,

I am trying to measure indoor carbon monoxide level with mics-4514.

I made breakout board by referring datasheet.

There are two eagle files. One file is base board with circuitry for preheating and some output resistance as mentioned in datasheet, and other file for mics module to make it modular and can be stacked on base board. 

I am using arduino sketch of Respira which uses Mics 4514 but not getting any output.

Few queries : 

1.What is role of R_load for CO and NO2? Datasheet mentioned that is should be at least 820 ohm.

2.I am using Arduino UNO to measure sensor reading, can this value of R_load be set to any thing?

3.What exactly is RO calibration (RO- 750000 for CO) represent?

4.Is calculation of analog voltage to ppm correct in respira sketch is correct?

 

Few links which i referred:

1. Sensor Datasheet- http://sgx.cdistore.com/ProductDetail/MICS4514-SGX-Sensortech-Limited/333417/pid=1263 

2. Respira- http://old.panstamp.com/announcements/respiraproject

3. https://github.com/ShawnHymel/MICS-4514_CO_and_NOx_Sensor_Breakout

Thanks

[bhavik...@gmail.com]

In the MiCS_4514 code, what is the value of the load resistance? And also in your code, why didnt you consider load resistance?