Determine the need to operate the test item during exposure to dust from the anticipated in-service operational requirements. If the test item must be operated, specify the time and periods of operation in the test plan. Include at least one 10-minute period of operation of the test item during the last hour of the test, with the test item's most vulnerable surface(s) facing the blowing dust. If the item is to be operated throughout a dust event in the field it is recommended that the item be operated throughout the dust exposures. Ensure the period of operation includes the essential operational requirements to include proper operation of environmental conditioning units (ECUs) for enclosures.
A build-up of dust will reduce the ability of the test item to shed the thermal load generated by electronics. If dust accumulations are expected in the field, perform the operational test without removing the dust. To fully evaluate the performance of the dust laden materiel in low wind speed and high temperature conditions, consider performing a high temperature operational test on the dust laden materiel using the procedures provided in Methods 501 or 505.
MIL-STD-810H
METHOD 510.7
Consider removal of the dust accumulation prior to operation of the test item. See section 4.1.1.9.
Consider manipulation of the test item as part of the operational test. This may uncover issues with binding or wear of moving parts. The test item should be manipulated in the same manner it would be utilized in the field in a dust laden environment. For example, the wear of hydraulic, pneumatic seals, or operator controls may not occur without repetitive use/manipulation of the equipment during testing.