The 3-m aspirator on M5 has been replaced (19 November 2015, 10:00 AM local time).
The aspirator moves air through /past the 3-m temperature sensors. A microswitch is activated by a flap that moves in the airflow. This tells us that the aspirator is actually working. A signal is stored in the DAS and used to quality control the temperatures.
The aspirator switch was not being activated more and more frequently over the last 4 weeks, leading to the temperature data being flagged. It looks like there was air moving through the channel, so data are probably OK, but based on the aspirator signals we’ve had to flag the data.