Certification of New Standard Reference Material 2806b Medium Test Dust in Hydraulic Oil

Abstract

A new material has been certified to become Standard Reference Material (SRM) 2806b -Medium Test Dust in Hydraulic Fluid. SRM 2806b consists of trace polydisperse, irregularly shaped mineral dust particles suspended in hydraulic fluid. The certified values of SRM 2806b are the projected area circular-equivalent diameters of the collected dust particles from the hydraulic fluid. The dimensional measurements were determined from the area of the collected dust particles using images obtained from automated scanning electron microscopy (SEM) followed by image analysis. An automated SEM and an automated image analysis software allowed the processing of over 29 million particles. The dimensional calibration of the SEM images (actual length per pixel and thus the actual projected diameters) are traceable to the NIST Line Scale Interferometer (LSI) through a NIST calibrated Geller MRS-4XY pitch standard. The certified diameters are correlated with the numeric concentration of particles greater than each diameter, referred to as the cumulative number size distribution. SRM 2806b is intended to be used to calibrate liquid-borne optical particle counters in conjunction with the reference method ISO 11171:2010.

Acceptance Testing Methodology for the Production of Standard Reference Material 2806: Medium Test Dust in Hydraulic Fluid

“…The analysis results shown here for both SRM 2806b and SRM 2806d led to both materials being accepted by NIST and subsequently certified. SRM 2806b was certified by microscopy and image analysis made traceable to the NIST line scan primary standard [ 9 ], and SRM 2806d was certified by an interlaboratory study containing 22 measurement results from 13 national and international participants [ 10 ]. The traceable link was through SRM 2806b, which was used as the calibrant both directly and indirectly through a secondary standard.…”

Primary standard for the number concentration of liquid-borne particles: extension of the diameter range from the micrometer to the sub-micrometer level and reduction of the measurement uncertainty

“…The measurement of the particle number concentration plays a critical role in the cleanliness control of ultrapure water (UPW) and chemicals in the semiconductor industry [1,2], the blood cell counting in clinical laboratories [3], the inspection of insoluble particulate matter in injections and ophthalmic * Author to whom any correspondence should be addressed. solutions in the pharmaceutical industry [4][5][6], and the monitoring of solid particle contamination in lubricant oils [7][8][9]. The calibration and routine testing of the particle counting instruments described in the above examples using appropriate reference materials (RMs) are essential for obtaining reliable results in concentration measurements.…”