Abstract.
We
reviewed
60
sensor
networks
and
15
related
efforts
(sensor
review
papers
data
accessibility
projects)
to
better
understand
the
landscape
of
stationary
low-cost
gas-phase
deployed
in
outdoor
environments
worldwide.
This
study
is
not
exhaustive
every
network
on
globe,
but
rather
exists
categorize
types
by
their
key
characteristics
explore
general
trends.
also
exposes
gaps
monitoring
date,
especially
regarding
availability
measurements
compared
particulate
matter
(PM),
geographic
coverage
(the
global
south,
rural
areas).
ground-based
that
measure
air
pollutants
into
two
main
subsets
based
deployment
type:
quasi-permanent
(long-term)
campaign
(short
medium-term)
commonplace
practices,
strengths,
weaknesses
networks.
conclude
with
a
summary
cross-network
unification
quality
control
efforts.
work
aims
help
scientists
looking
build
best
practices
common
pathways,
aid
end
users
finding
datasets
meet
needs.
Spatial
variation
of
indoor
and
outdoor
PM2.5
within
three
states
for
a
5-year
period
is
studied
using
regulatory
low-cost
PurpleAir
monitors.
Most
these
data
were
collected
in
an
earlier
study1
investigating
the
relative
contribution
indoor-generated
outdoor-infiltrated
particles
to
exposures.
About
260
monitors
~10,000
~4,000
are
included.
Daily
mean
concentrations,
correlations,
coefficients
divergence
(COD)
calculated
pairs
at
distances
ranging
from
0
(collocated)
200
km.
We
use
transparent
reproducible
open
algorithm
that
avoids
proprietary
algorithms
provided
by
manufacturer
sensors
PA-I
PA-II
The
available
on
API
website
under
name
“PM2.5_alt”.
This
validated
several
hundred
separated
up
0.5
spatial
outdoors
homogeneous
with
high
correlations
least
10
km,
as
shown
COD
index
0.2.
There
also
steady
improvement
concentrations
increasing
distance
indoors
not
even
<100
m.
document
substantial
differences
between
Federal
Reference
Methods
(FRM)
Equivalent
(FEM).
Sensors,
Journal Year:
2023,
Volume and Issue:
23(3), P. 1160 - 1160
Published: Jan. 19, 2023
Low-cost
monitors
make
it
possible
now
for
the
first
time
to
collect
long-term
(months
years)
measurements
of
potential
indoor
exposure
fine
particles.
Indoor
is
due
two
sources:
particles
infiltrating
from
outdoors
and
those
generated
by
activities.
Calculating
relative
contribution
each
source
requires
identifying
an
infiltration
factor.
We
develop
a
method
periods
when
factor
not
constant
searching
relatively
constant.
From
initial
regression
on
outdoor
particle
concentrations,
Forbidden
Zone
can
be
defined
with
upper
boundary
below
which
no
observations
should
appear.
If
many
appear
in
Zone,
they
falsify
assumption
single
This
useful
quality
assurance
feature,
since
investigators
may
then
search
subsets
data
few
Zone.
The
usefulness
this
approach
illustrated
using
examples
drawn
PurpleAir
network
optical
monitors.
An
improved
algorithm
applied
reduced
bias,
precision,
lower
limit
detection
than
either
proprietary
algorithms
offered
manufacturer
sensors
used
Sensors,
Journal Year:
2023,
Volume and Issue:
23(17), P. 7657 - 7657
Published: Sept. 4, 2023
Low-cost
Particulate
Matter
(PM)
sensors
offer
an
excellent
opportunity
to
improve
our
knowledge
about
this
type
of
pollution.
Their
size
and
cost,
which
support
multi-node
network
deployment,
along
with
their
temporal
resolution,
enable
them
report
fine
spatio-temporal
resolution
for
a
given
area.
These
have
known
issues
across
performance
metrics.
Generally,
the
literature
focuses
on
PM
mass
concentration
reported
by
these
sensors,
but
some
models
also
Particle
Number
Concentrations
(PNCs)
segregated
into
different
ranges.
In
study,
eight
units
each
Alphasense
OPC-R1,
Plantower
PMS5003
Sensirion
SPS30
been
exposed,
under
controlled
conditions,
short-lived
peaks
generated
using
two
combustion
sources
PM,
exposing
sensors'
particle
distributions
quantify
better
understand
low-cost
range
relevant
environmental
The
PNCs
were
analysed
characterise
sensor-reported
distribution,
determine
whether
can
follow
transient
variations
observed
reference
instruments
relative
impact
variables
performances
sensors.
This
study
shows
that
OPC-R1
at
least
five
ranges
independently
from
other,
other
all
not
independent
other.
It
demonstrates
tested
here
could
track
variation
PNCs,
closely
distribution
between
it
composition
are
more
impactful
sensor
measurements
than
humidity.
Abstract.
We
reviewed
60
sensor
networks
and
15
related
efforts
(sensor
review
papers
data
accessibility
projects)
to
better
understand
the
landscape
of
stationary
low-cost
gas-phase
deployed
in
outdoor
environments
worldwide.
This
study
is
not
exhaustive
every
network
on
globe,
but
rather
exists
categorize
types
by
their
key
characteristics
explore
general
trends.
also
exposes
gaps
monitoring
date,
especially
regarding
availability
measurements
compared
particulate
matter
(PM),
geographic
coverage
(the
global
south,
rural
areas).
ground-based
that
measure
air
pollutants
into
two
main
subsets
based
deployment
type:
quasi-permanent
(long-term)
campaign
(short
medium-term)
commonplace
practices,
strengths,
weaknesses
networks.
conclude
with
a
summary
cross-network
unification
quality
control
efforts.
work
aims
help
scientists
looking
build
best
practices
common
pathways,
aid
end
users
finding
datasets
meet
needs.
Abstract.
We
reviewed
60
sensor
networks
and
15
related
efforts
(sensor
review
papers
data
accessibility
projects)
to
better
understand
the
landscape
of
stationary
low-cost
gas-phase
deployed
in
outdoor
environments
worldwide.
This
study
is
not
exhaustive
every
network
on
globe,
but
rather
exists
categorize
types
by
their
key
characteristics
explore
general
trends.
also
exposes
gaps
monitoring
date,
especially
regarding
availability
measurements
compared
particulate
matter
(PM),
geographic
coverage
(the
global
south,
rural
areas).
ground-based
that
measure
air
pollutants
into
two
main
subsets
based
deployment
type:
quasi-permanent
(long-term)
campaign
(short
medium-term)
commonplace
practices,
strengths,
weaknesses
networks.
conclude
with
a
summary
cross-network
unification
quality
control
efforts.
work
aims
help
scientists
looking
build
best
practices
common
pathways,
aid
end
users
finding
datasets
meet
needs.
