Oxygen in air is measured using a galvanic cell sensor which connects to the external sensor sockets on the DrDAQ using the supplied three metre lead. As a galvanic type sensor does not require a power supply you can simply plug in the sensor and you are ready to measure.
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The voltage output from the DD103 Oxygen sensor responds to the partial pressure of oxygen in air. The standard units for partial pressure are kPa. However, gas sensors that respond to partial pressure are typically calibrated to read out in mole fraction of the gas in air, which has units of moles of oxygen (O2) per mole of air. These units are directly converted to percentage of O2 in air by the DrDAQ data logger. The concentration of oxygen in our atmosphere is 20.95%, and this value, to 4 significant digits, has not changed for decades. This means that the oxygen sensor can be easily calibrated (provided you do not breathe on the sensor when it is being calibrated - our exhaled breath is about 17% oxygen.) When calibrated the oxygen sensor has an accuracy of 1% . Unlike previously available oxygen sensors, the DD103 Oxygen in air sensor can measure the full 0 to 100% range. This makes it ideal for many chemistry, biology and physics experiments. |
Experiments for which the oxygen in air sensor and DrDAQ lend themselves particularly well include:
- Monitoring how chemical reactions consume or produce oxygen
- Observation of how organisms consume oxygen
- Observation of how plants produce oxygen during photosynthesis
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These experiments are just a few of many in which oxygen in air measurement plays a crucial role. Our science experiment "burning oxygen" shows just one possible experiment for the oxygen sensor. For further experiments that use the oxygen sensor and over sixty other interesting and educational experiments visit the Pico Technology library of science experiments | |
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