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No. 7
Minimum Calibration and Training Requirements for ATI
Aerosol Photometers At a minimum, one 8-hour
training session at the ATI facility is required to learn
proper aerosol photometer calibration and service.
To properly calibrate and service an aerosol
photometer, an appropriate work area is required. The work
area should be equipped with a complete set of hand tools,
special instrumentation and equipment, as listed below. All
instrumentation should be certified by the NIST (National
Institutes of Science and Technology) or other recognized
organization.
• A 100 micrograms per liter aerosol
source for both Poly-Alpha Olefin (PAO) & Di-2-Ethylhexyl
Phthalate (DOP).
------------ATI part T930-1118 (120VAC),
T930-1187 (220VAC) or equivalent.
• A pico-ampere Source capable of supplying
down to 1 x 10 -11 DC amperes.
------------Keithley model 6220 or equivalent.
• A digital multi-meter capable of measuring
1 millivolts to 700 volts, AC/DC, with a minimum of four digits
of resolution.
------------Fluke model 45 or equivalent.
• Electronic balance with 1-milligram
resolution (0.001 gram).
------------Model FX-200, manufactured by
AnD, or equivalent
• Vacuum source, 32 lpm minimum @ 5"
mercury.
------------Gast model 1531 or equivalent.
• Hygrometer & thermometer for recording
relative humidity and temperature.
• A pressure indicator, 0 to 60-psig,
with a .25psig resolution.
• A flow meter or gas meter capable
of measuring 28.3 lpm ± 0.5 lpm.
The aerosol source is to adjust the internal
reference features to the correct level. ATI can provide this
aerosol source that employs both Poly-Alpha Olefin (PAO) and
DOP Aerosol Generator. To validate the 100 micrograms per
liter aerosol source the electronic balance is used to perform
a gravimetric verification of the aerosol concentration. The
balance, in conjunction with a 47-millimeter filter media
holder and correct pickup media, can be used to gravimetrically
validate and verify that the aerosol source is producing the
correct concentration level of 100 micrograms per liter (ug/l).
Gravimetric verification should be performed on a monthly
basis.
The flow meter or gas meter is used for two
purposes. The main purpose is validation and verification
of the aerosol photometer flow, which should be 28.3 ±
2.83 lpm. The other purpose is to monitor and measure the
amount of flow drawn through the 47-millimeter pickup media
when validating the 100-ug/l-aerosol source.
The pico-ampere source is used to drive the
photometer electronics and readout with controlled signals
that are NIST traceable.
The NSF and most ISO-9000 quality programs
use the pressure indicator to provide calibration data on
aerosol generator pressure gauges that is now required.
• Optional - A traceable laser aerosol
spectrometer may be used to provide calibration data on aerosol
generator particle size distribution. Companies with ISO-9000
quality programs may require this.
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