Hello,
I currently am using the LMP91000EVM with SPIO-4 hooked up to my Windows 7 x64 computer running the LMP91000 v2.0.3.0 evaluation software. I am attempting to use the setup with a Nitric Oxide (NO) sensor element from Nemoto. This sensor element has all the same specs as the CityTech 4NT element that is included with the program.
I select the sensor and then tell the program to "Write all registers to board". I then go to the measurement tab and tell the reading to run continuously leaving it on the default display type of "Output Voltage (mV)". I see the bias voltage charge the sensor and finally after about 2-3 minutes it settles out to about 460mV. I stop the reading and switch to display "Concentration (ppm)" and restart the display. The range of the sensor is 250 ppm, I apply a 100 ppm cal gas and will see the reading change maybe 2 or 3 ppm. I know if i adjust the sensitivity and offset I can make the reading start at almost 0 ppm but the sensor never reads more then 2 or 3 ppm.
Is there a setting I am missing or forgetting a step? Any other suggestions I can try? I really like the theory behind this chip but I so far have not had much success with it.
Thanks for any assistance.