BS ISO 09022-23:2016 pdf download – Optics and photonics — Environmental test methods Part 23: Low pressure combined with cold, ambient temperature and dry or damp heat
This part of lS0 9022 specifies the methods relating to the environmental tests of optical instrumentsincluding additional assemblies from other fields (e.g. mechanical, chemical, and electronic devices).under equivalent conditions, for their ability to resist the influence of low pressure combined withcold, inciuding the potential condensation and freezing of moisture, ambient temperature, and dry ordamp heat.
This part of IS0 9022 is applicable to optical instruments including additional assemblies from otherfields,designed for operation and/or transport in high mountainous areas or on board aircraft ormissiles.
The purpose of the testing is to investigate to what extent optical, climatic,mechanical, chemical,and electrical (including electrostatic) performance characteristics of the specimen are affected bycombined low pressure and low, ambient, or high temperature.Furthermore, the additional effects ofmoisture condensing and freezing on the instrument or components can be determined.Examples areinstruments which are installed or externally mounted on aircraft or missiles or transported insideaircraft or flying objects not providing any pressure equalization.
Annex A explains the intent of the different types of tests.
The following documents, in whole or in part, are normatively referenced in this document and areindispensable for its application. For dated references,only the edition cited applies. For undatedreferences, the latest edition of the referenced document (including any amendments) applies.
ISO 9022-1,Optics and photonics —Environmental test methods —Part 1: Definitions, extent of testingISO 9022-8,Optics and photonics — Environmental test methods — Part 8:High internal pressure, lowinternal pressure, immersion
3 General information and test conditions
Ambient temperature as understood by this part of ISo 9022 is (23± 3) °C.
The values of temperatures and climatic conditions specified in Table 1 to Table 6 are selected fromISO 9022-2,conditioning methods 10,11, and 12.
The size of the test chamber and the setup of the specimens shall be chosen in such a way that a uniformtemperature for all specimens within the test chamber is ensured.
For conditioning methods 45,46,50, and 51, air circulation in low-pressure cabinets or low-pressurechambers is required. The low-pressure chamber, itself, can either be equipped as a thermal chamberor be installed in a thermal chamber.
For conditioning methods 47 to 49, a climatic test chamber is required. Three different test methods are used to test combined damp heat and low internal pressure resistance of optical instruments. Dew on the specimen is admissible.
The individual test steps shall be performed directly one after another. Interruption of the test is not admissible. In addition for conditioning method 47, if condensation is produced, the specimens shall be protected against falling drops. In addition for conditioning method 48, a low-pressure container is also required. In addition for conditioning method 49, the specimens shall have a test connection for evacuation and pressure measurement, as described in ISO 9022-8. Changes in temperature shall be effected sufficiently slowly not to cause any damage to the specimen. Shock-type air pressure changes shall be avoided unless they are likely to be encountered in the natural environment.
4.1 Conditioning method 45 — Low ambient pressure combined with ambient temperature See Table 1.
4.2 Conditioning method 46 — Low ambient pressure combined with dry heat
See Table 2.
4.3 Conditioning method 47 — Low internal pressure combined with damp heat,pressure difference low See Table 3 and Figure 1.
Conditioning method 47 shall be used for optical instruments where demands made on their sealing (low pressure resistance) are low, e.g. instruments which comply with the requirements of the degrees of severity 01, 02, 07, and 08 of conditioning method 81 in ISO 9022-8.
4.4 Conditioning method 48 — Low internal pressure combined with damp heat, pressure difference medium See Table 4.
Conditioning method 48 shall be used for optical instruments where demands made on their sealing (low pressure resistance) are medium, e.g. instruments which comply with the requirements of the degrees of severity 03, 04, 09, and 10 of conditioning method 81 in ISO 9022-8.BS ISO 09022-23 pdf download.