Downloaded from https://www.everyspec.com MIL-STD-810D 19 July 1983 (b) Silica flour has been widely used in dust testing and ~ contains 97 to 99 size distribution percent (by weight) silicon dioxide (S102). The following applies to both red china clay and eilica flour: 100 percent shall pass through a 100 mesh screen. 98 ~ 2 percent shall pass through a -140mesh screen. ,. 90 ~ 2 percent shall pass through a 200 mesh screen. 75 * 2 percent ehall pass through,a~325 mesh screen. ..-. I (2) Unless otherwiee speoified, the sand suggeeted to be used in the large-partiole test is silica sandz/ (at least 95% by weight Si02).
The amount 1.OS ~ 0.5% of the sand shall be retained by a 20 mesh screen (85o Pm) , I 1.7$ ~ 0.5% by .a 30 meeh screen (590!.I m), 14.8$ ~ 1% by a 40 mesh screen (420 !Jm),37.0% ~ lZ by a 50 mesh screen (2971.IzI), 28.6$1 1% by a 70 mesh screen (210 urn),12.7% ~ 1% by a 100 mesh screen (149 Mm) , and 5.21 + 1% shall . Dass a 100 mssh screen. The sand shall be of subangular structure with a mean Krumbein number (roundness factor) equal to 0.2 and-a mobs. hardness factor of 7 e. ~ (1) maintained at dust test shall be 10.6 ~ 7 g/m3 (O.3 ~ O.2 g/ft3) unless-otherwise specified.
Thie unrealistic and is used because of the limitations of most The duet concentration f o r the blowinu figure is not chambers. The sand concentration& shall be as follows unless otherwise 1 specified.(2) I (a) For test.items likely to be used close to aircraft (iu;h as helicopters) operating over unpaved surfaces, 2.2 ~ O.5 g/m3 (O.0623 ~ 0.015 S[!%3). (b) For test iteme never used or never exposed close to operating aircraft, but which may be found near operating surface vehicles, 1.1 ~ 0.25 g/m3 (0.033 k 0.0075 g/t%3). (c) For test items that will be subjected only to natural conditions, 0.177 g/m3 (0.0065 g/ft3). ,. f. ~.
The configuration of the test item muet reproduce, as closely as technically possible, the configuration that it would . a.$aumeduring storage or use, such as: 2/ Naval Weapons Center Large Particle Blowing Sand Procedure. 3/ MIL-STD-210. ~ MSTHOD 510.2 19 JUIY 1983 510.2-4