and traceable and above all accurate. Since we are
monitoring invisible particles, how can we be sure
the data is good data?
Finding the weak points
Where are the vulnerable areas where data from
a particle counter could be questionable and the
integrity compromised?
There are several areas to look closely at when
selecting the right particle counter for your monitoring system and mitigating data integrity risks in
order to minimize and reduce product recall and
further investigations.
Location: Are you 100 percent sure that the
particle counter is in the right location? Is the location ID built into the remote sensor? Are we sure
that after the unit comes back from service that it
has been put back in the right location? Human
error plays a major role and it has been shown that
mistakes can occur and remote particle counters
coming back from service are mistakenly placed at
the wrong location. What does this mean? As the
data coming from the sensor is picked up from the
EMS from the wrong location, a small mistake can
have a huge impact and lead to major data integrity
issues.
Solution: Look for remote particle counters with
technology where the location ID is embedded in
the location mounting bracket rather than the par-
ticle counter. This way, any remote particle counter
can be inserted and the data will be confirmed
from the right location 100 percent of the time.
Particle count data integrity: Current airborne
particle counters use light scattering technology
with a laser diode and a photo detector to convert
light scattered from a particle into raw electrical
data (mV signal) and the particle counter elec-
tronic circuits can interpret this data for particle
size accuracy and particle count accuracy. The
level of light scattered is proportional to the size of
the particle.
Solution: Choose a particle counter that has the
best “self-diagnostics” which constantly monitor
the sensor’s health. The more diagnostics there are,
the more likely a service alarm will trigger an event
that can be managed quickly and without major
data compromises or product integrity questions
being raised.
Laser health: If the laser light is not running
at its optimum intensity then there is an accura-
cy error factor that comes into play. Laser health
should be monitored consistently and error signals
communicated if laser levels drop below optimum
ranges.
Solution: Confirm that laser power has a feedback loop that is constantly monitored to keep laser
power at optimum levels, and if not, a laser fault
service alarm should be issued to notify users there
is an issue with the laser and therefore the data
could be compromised and not accurate.
