The inlet pressure of the ACSM at Eastern north Atlantic exhibited a decline beginning
around 2014-10-15. This can be seen in the inlet pressure history and the N2 and airbeam
signal. The cause for this is an obstruction in the 100 µm critical orifice. The
instrument was shut down in December while waiting for a new critical orifice to be delivered to
the site in the Azores. A new procedure for cleaning the critical orifice that did not
require an ultrasonic bath was tried in 2015-02-10 was successful in unblocking the
orifice. This could be a result of large sea salt particles in the system because of the
proximity of the site to the ocean.