505.7-3 OTHER ENVIRONMENTAL FACTORS TO BE CONSIDERED
Attention is drawn to the possible cooling effects of air flow over materiel. In practice, high solar radiation conditions are rarely accompanied by complete absence of wind. It may be necessary, therefore, to assess the effect of different air velocities over materiel under test. The materiel specification should state any special requirements in this respect. It is essential, therefore, to measure and control the rate of air flow in order to maintain the required air temperature at the test item. Excessive or un-controlled air flow can also result in misleading errors in open-type thermopiles used to monitor radiation intensity; ventilation of pyranometers may be necessary to keep the glass dome cool.
3.1 Pretest
The following information is required to conduct solar radiation tests adequately.
- a. General. Information listed in Part One, paragraphs. 5.7 and 5.9, and Annex A, Task 405 of this Standard.
- b. Specific to this Method.
- (1) Appropriate diurnal cycle (for Procedure I) to include humidity if appropriate.
- (2) Test item operational requirements.
- (3) Spectral power distribution of the source lighting (e.g., to reproduce conditions of a previous test).
- (4) Any additional guidelines.
- (5) Temperature/radiation measurement techniques and locations.
- (6) Substrate or method of test item mounting.
- (7) Wind speed.
- (8) Identify sensor location(s) for determination of peak response temperature stabilization.
- (9) Location and mounting configuration for the pyranometer (see Annex B, paragraph 1.3)
- c. Tailoring. Necessary variations in the basic test procedures to accommodate environments identified in the LCEP.
3.2 During Test
Collect the following information during conduct of the test:
- a. General. Information listed in Part One, paragraph 5.10, and in Annex A, Tasks 405 and 406 of this Standard.
MIL-STD-810H
METHOD 505.7
- b. Specific to this Method.
- (1) Record of chamber temperatures (and humidity if required) and light intensity versus time conditions.
- (2) Record of the test item temperature-versus-time data for the duration of the test.
- (3) Record of test wind speed.
3.3 Post-Test
The following post-test data shall be included in the test report.
- a. General. Information listed in Part One, paragraph 5.13, and in Annex A, Task 406 of this Standard.
- b. Specific to this Method.
- (1) Location of temperature sensors on the test item.
- (2) Test item response temperatures (and humidity if required), and number of diurnal cycles or exposure periods.
- (3) Record of test wind speed.
- (4) Spectral power distribution of the source lighting (e.g., to reproduce conditions of a previous test).
- (5) Solar lamp bank identification.
- (6) Any additional data required.
- (7) Any deviations from the original test plan – to include wind speed (if necessary to adjust it).
- (8) Any deviation from the required spectral power distribution as stated in Table 505.7-I, and justification.
- (9) Location and mounting configuration for the pyranometer