This article applies to Vernier Go Direct sensors. For more information from Vernier on the accuracy of their devices, please check out their help article about the uncertainty of their sensors.
Uncertainty is a tricky thing in science: it is influenced not only by the tools, but by the user and the environment of the tools. As such, there is no one answer that would explain the uncertainty of a sensor.
Each Vernier Go Direct sensor DOES have a reported specifications that may help you in your experimental design. Check the table below for valuable planning information. To access the official Vernier user manual, click on the sensor's name. Click here for a list of all Vernier sensors and their manuals.
1 ppm CO2
0 to 1,000 ppm ±100 ppm
1,000 to 10,000 ppm ±5% of reading +100 ppm
10,000 to 50,000 ppm ±10% of reading
50,000 to 100,000 ppm ±15% of reading
±0.1 N (force)
± 0.2 pH units
0.25 mm, displaying to nearest 1 mm (position)