Measurement of the 100 nm NIST SRM 1963 by Differential Mobility Analysis.
Measurement of the 100 nm NIST SRM 1963 by Differential
Mobility Analysis.
(1523 K)
Mulholland, G. W.; Bryner, N. P.; Croarkin, C.
Aerosol Science and Technology, Vol. 31, 39-55, 1999.
Keywords:
differential mobility analysis; electrical mobility;
mobility; monosize particles; particle size;
transmission electron microscopy
Abstract:
The number mean diameter of 100 nm NTST Standard
Reference Material (SRM) 1963 was measured to be 100.7
nm with an expanded uncertainty at the 95% confidence
level of 1.0 nm by measurement with the differential
mobility analyzer (DMA). The low level of uncertainty
resulted from the use of the 1.0 mum SRM 1690 for
calibrating the DMA. The largest single component of
the Type B (systematic) uncertainty was a 0.29 nm
uncertainty in the calibration diameter. Measurements
of the 0.3 mum SRM with the calibrated DMA give results
within 0.001 mum of the certified diameter. Results
obtained by other investigators using transmission
electron microscopy (TEM), angle dependent light
scattering, electro-gravitational aerosol balance, and
atomic force microscopy are consistent with this DMA
value. The 100 nm NIST SRM 1963 and the Japanese 100 nm
Calibration Standard are shown to differ by 10% based on
TEM analysis and DMA measurements. This size difference
has a significant effect on the calibration of scanning
surface inspection systems and optical particle
counters.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899