Selecting a sensor is primarily based on three factors:

• Accuracy: How well the sensor measures what you are interested in.
• Usability: How easy the sensor is to deploy and use e.g. does it need a power supply, do filters need to be frequently replaced etc.
• Cost: How expensive the devices are to buy and run.

Our sensor summary page plans to inform the first of these (accuracy) by collating results from sensor tests that have been submitted to the website. The page shows various statistical measures of accuracy over hourly, daily and annual periods. The measures include:

• R² : a measure of how reliable the sensor is
• Slope: a measure of how well the sensor responds
• Uncertainty at the Limit value: a measure of how useful it is at the appropriate limit value, which is the most important concentration in the UK.

These are also show as plots which help to visualise the data.

You can select which types of users you wish to include or exclude in the test summary and see how it affects the figures and plots.