Redacted data

This page will explain the reasons why data from your AQMesh pods is sometimes redacted.

Why is it redacted?

• Data is only redacted when we are uncertain that it will meet to required standards \ published specifications
• We don’t want customer to use or publish bad data during their analysis or project
• Data is redacted during the stabilisation period because the sensor output is unstable when first deployed
• Data is temporarily redacted during rebasing because it will have the wrong offset until rebased
• Data is redacted during a sensor failure because the sensor has failed the readings cannot be trusted
• Data is redacted because certain gases require cross-compensation in order to give accurate readings if the other sensor fails then reading from the target sensor cannot be trusted
• Data is redacted in extreme environments because the readings cannot be trusted

When is data redacted?

• During the stabilisation period (the first two days after switch on) when a pod is first deployed
• Temporarily during rebasing although this data is reinstated once rebase is complete and is flagged as rebased
• During a sensor failure
• Due to cross-gas errors
• Due to destabilisation of the sensor following very rapid rises or falls in temperature and\or humidity
• Due to extreme environments when either the temperature and / or humidity is outside the operating range of the sensor

How does it affect your data?

The ppb reading is replaced with a coded error value to indicate the type of redaction:-

• -999 stabilisation
• -998 rebasing
• -996 sensor failure
• -995 cross-gas compensation sensor failure
• -993 destabilisation of a sensor following an unnatural change in temperature or humidity
• -992 extreme environment