Customer:
I need gas sensors for an experimental setup to measure gas composition from an autoclave system. The gas would first flow into a separate chamber where the sensors would be located, so ideally they would need to withstand a few bar of pressure. I need to measure the following gases:
- Nitrogen (±0.1% accuracy), maximum concentration up to 95%
- Hydrogen (±0.01% accuracy), maximum concentration about 4%
- CO2 (±0.01% accuracy), maximum concentration about 1%
- Methane (±0.01% accuracy; 0.001% would be ideal), maximum concentration about 10%
It would also be good to be able to measure:
- Oxygen (±0.1% accuracy), maximum concentration about 10%
- Possibly Argon (±0.01% accuracy), maximum concentration about 20%
Most of your sensors list specifications like “100-1000 ppm”. Do you have anything that would be suitable for my application?
Originally submitted via email support on 21 November 2024. Migrated to the forum for community visibility.
Soldered Support:
We don’t have a nitrogen sensor, only NO2. For the gases you’re measuring:
However, these sensors (except the CO2 sensor) are relatively simple sensors and are not designed to deliver high-precision measurements. To obtain accurate values in ppm, you would also need to perform your own calibration and interpret the raw values output by the sensors. One approach would be to perform measurements in a controlled environment at a fixed ppm value, determine the raw data from the sensors, and then map this to ppm. This would improve sensor accuracy, but they would still fall outside the tolerance limits you specified.
Your application seems quite specific, and a higher-quality sensor might be required.
One possible exception could be the MH-Z19 CO2 sensor, which has an accuracy of ±50 ppm + 5%. Here is a page with more information: https://emariete.com/en/sensor-co2-mh-z19b/.
Our most precise sensors are electrochemical gas sensors. Check out this product line to see if there is a suitable sensor for your gas. For each of these sensors, you can find further technical details on the manufacturer’s website.