The document discusses particulate matter monitoring in ambient air. It describes conventions for classifying particle sizes based on where they deposit in the respiratory system. It outlines the evolution of particulate matter monitoring from total suspended particulates to PM10 to PM2.5. It also describes features of the Indian approach to particulate monitoring using respirable dust samplers and the procedures for operating and maintaining these samplers.

1. Particulates in Ambient Air
The Size Conventions
• Health effects are related to
where the particles get deposited
– Inhalable: Particles that can be
breathed into the nose or mouth.
– Thoracic: Particles that penetrate
into the respiratory tract below the
larynx.
– Respirable: Particles that reach
deep into the alveolar region of the
lung
These size conventions were co-developed and adopted by the International Organization
for Standardization (ISO), the American Conference of Governmental Industrial Hygienists
(ACGIH), and the Comité European de Normalization (CEN) in the early 1990s..

2. Measurement of Particulate
Pollutants in Ambient Air
• Initial approach measured the Total
Suspended Particulate Matter (TSP)
• Much of the TSP would not enter the
nose or be retained in the upper
respiratory tract. This led to the
development of PM10 samplers.
• It is now believed that most of the
health impacts are related to Fine
Particles that reach deep into the lungs
leading to development of Fine Particle
or PM2.5 Samplers.

3. Measurement of Particulates
Features of the Indian
approach
• Separation of Respirable fraction
through a Cyclone leads to:
– a very compact instrument as compared to
the bulky Impactor based systems adopted
by the West.
– Recovery of the coarse fraction allowing
measurement of both TSP & RSP in the
same equipment.
• Adoption of Sampling systems instead
of sensor based - direct reading sys:
– Keeps costs affordable
– Simpler equipment is easier to maintain
– Minimal requirement of Calibration &
support infrastructure.
– Physical sample becomes available for
analysis of constituents
• Use of Indigenous equipment ensures
availability of Service Support

4. Evolution of the RDS
• First developed in 1990-91
– Two stage system for separation of
coarse and fine fractions, developed
in collaboration with NEERI.
– Envirotech introduced the RDS
almost 4 years before RSPM was
included in the Ambient Air Quality
Standards in India.
– Initially introduced as APM451 and
later upgraded to APM460.
• Today Envirotech produces three
variants of the RDS:
– APM460BL
– APM460NL
– APM460NLDX

5. The Improved RDS
Envirotech APM 460BL
• Brushless Blower
– Sampling rate does not fluctuate
with variation in mains voltage.
– Low equipment downtime and
maintenance costs.
• Interference to TVs eliminated
and Audible Noise reduced to
less than half of previous levels.
• Castor Wheels added
for easier movement of the
instrument in the field.
• Small bulb provided for easier
handling at night.

6. Envirotech APM 460NL
For Research & Intensive use
• Practically NOISE-LESS operation
of the APM 460NL makes it ideal for
monitoring air quality in residential
areas or near hospitals, libraries etc.
• Main features of the APM 460NL
– Sampling rate does not fluctuate
with variation in mains voltage.
– Brushless Blower designed for
trouble free operation even with
intensive use.
– No interference to TVs.
– Low equipment downtime and
maintenance costs.
However the equipment is heavy
and frequent re-location should be
avoided.

7. Envirotech APM 460NLDX
Main Features:
•Flow rate
automatically
controlled to
compensate for Dust
loading on the filter.
•Auto Shut-off if flow
rate drops below
0.85m3/min.
•Only instrument that
conforms to BIS
•Low Noise and
Brushless Blower

8. Monitoring Particulates in
Ambient Air - Procedure &
Precautions
• Preparation
– Inspect the filter for pinholes,
particles and imperfections. Assign
filter identification numbers.
– Establish a system of filter batch
numbers & look-out for fakes.
– Equilibrate each filter for at least 24
hrs. in a controlled environment
having:
• Temperature 15 - 30 degrees C
• Humidity 20-45%
– Weigh each filter & record the initial
weight. For HVS / RDS balance with
0.1mg accuracy is required.
– For low / medium volume samplers
(flow rate <0.5m3
/min) balance with
better sensitivity will be needed.

9. Monitoring Particulates in
Ambient Air - Procedure &
Precautions
• Operation
– Install pre-weighed filter, set the
timer, record Time-totalizer reading
and turn ON the sampler flow.
– Allow it to establish normal running
temperature and record flow rate.
– If sampling rate is outside
acceptable limits check for leaks,
filter displacement etc.
– Record sample information - site
location, Sample date, Filter ID No.
– On completion of sampling period
record flow rate and time-totalizer
reading.
– Carefully remove the filter - touch
only outer edges, and store in an
appropriate carrier.

10. Monitoring Particulates in
Ambient Air - Procedure &
Precautions
• Post Operation
– Work out the average flow rate.
– Record any factors such as
meteorological conditions,
construction activity, dust storm etc.
that might affect your results.
– Transport the filter to the
equilibrating environment as soon
as possible.
– Equilibrate the filter under the same
conditions for at least 24 hours.
– Immediately after equilibration
weigh and record the post sampling
filter weight along with filter ID No.