The UV Flux oxygen sensor module from CO2Meter uses a LuminOx LOX-02 optical sensor. It is an excellent sensor for the price, but how does it compare to other low cost oxygen sensors for Arduino?
Electrochemical Oxygen Sensors
Many low cost electrochemical oxygen sensors for Arduino projects like the Gravity: I2C Oxygen Sensor or the Grove Oxygen Sensor Pro have entered the market over the last few years. These are fine sensors for the hobbyist market, but their specifications do not match the LuminOX LOX-02 sensor for scientific applications.
- Typical electrochemical oxygen sensors are accurate to within 0.1 to 0.15% O2 by volume with a T90 < 15 seconds response time and a 2 year lifespan.
- Typical optical oxygen sensors have a 0.01% resolution with a T90 < 10 seconds and a 5+ year lifespan.
In addition, unlike electrochemical oxygen sensors, optical oxygen sensors contain no hazardous materials, and are RoHS & REACH compliant.
Optical Oxygen Sensors
A much more expensive oxygen sensor like the Piccolo2 sensor by PyroScience is accurate, but can it be matched by a low cost sensor like the UV-Flux?
This was the question raised by Heinz Surbeck, President of Nucfilm GmbH in Switzerland. Mr Surbeck is a physicist working in the field of environmental monitoring. For 20 years he was head of the Swiss Federal Environmental Radioactivity Lab, then for 10 years a Senior Scientist/Lecturer at the University of Neuchatel's Center for Hydrogeology and a lecturer at the Earth Sciences Dept of the ETH-Zurich.
In one of his company’s projects, Mr. Surbeck needed oxygen sensors to help fish farms mitigate their supersaturation problemsThis included continuous monitoring of oxygen, carbon dioxide and total dissolved gas pressure (TDGP) to determine nitrogen partial pressure that is important for the fish. At nitrogen partial pressures in the water above partial pressure in the atmosphere, trout fish get sick (bubble disease).
“I'm well equipped with optical oxygen sensors from PyroScience - the best you can have - but I'm always looking for new innovative sensors that may be cheaper than my ‘Rolls-Royce’,” Surbeck said.
To compare the sensors, Surbeck devised an experiment where both sensors were subjected to the same air samples over the course of an hour. Serial output was run through an Arduino PRO, then to a serial to USB converter for display on a PC. What he found was that the UVFlux sensor gave almost identical results to the Piccolo2.
The Piccolo2 cost 10 times as much as our UV Flux oxygen sensor module, but produces virtually the same results. This makes our sensor worth serious consideration for scientists and researchers who need an accurate, low cost oxygen sensor for Arduino.