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GJB 150 consists of the following 28 parts under the general title Laboratory environmental test methods for military materiel:
a) Part 1: General requirements;
b) Part 2: Low pressure (altitude) test;
c) Part 3: High temperature test;
d) Part 4: Low temperature test;
e) Part 5: Temperature shock test;
f) Part 7: Solar radiation test;
g) Part 8: Rain test;
h) Part 9: Damp heat test;
i) Part 10: Fungus test;
j) Part 11: Salt fog test;
k) Part 12: Sand and dust test;
l) Part 13: Explosive atmosphere test;
m) Part 14: Immersion test;
n) Part 15: Acceleration test;
o) Part 16: Vibration test;
p) Part 17: Acoustic noise test;
q) Part 18: Shock test;
r) Part 20: Gunfire vibration test;
s) Part 21: Wind pressure test;
t) Part 22: Icing/freezing rain test;
u) Part 23: Motions and inclinations test;
v) Part 24: Temperature-humidity-vibration-altitude test;
w) Part 25: Vibro-acoustic/temperature test;
x) Part 26: Contamination by fluids test;
y) Part 27: Pyroshock test;
z) Part 28: Acidic atmosphere test;
aa) Part 29: Ballistic shock test;
bb) Part 30: Ship shock test.
This is Part 10 of GJB 150, which replaces GJB 150.10-1986 Environmental test methods for military equipments - Fungus test.
The following main changes have been made with respect to GJB 150.10-1986 (the previous edition):
a) the Clause “Test conditions" in GJB 150.10-1986 is deleted, and the tailoring guidelines for determining test methods, test sequences, test procedures and test conditions are added;
b) the requirements for test information are added;
c) the test strains are changed from one group to two groups;
d) the test temperature and humidity are changed from the original alternating cycle to the constant cycle;
e) the wind speed in the workspace of the test chamber is different from the original;
f) the requirements for ventilation in the test procedures are cancelled;
g) the evaluation grade of test piece appearance effects is no longer divided according to the mold growing area;
h) the documents related to the test safety information of this part are used for reference.
This part was proposed by the Electronic Information Base Department of the General Armaments Department of the PLA.
The previous edition of this part is as follows:
GJB 150.10-1986.
Laboratory environmental test methods for military materiel - Part 10: Fungus test
1 Scope
This part specifies the purpose and application, tailoring guidelines, information requirements, test requirements, test process and result analysis of fungus test carried out in military materiel laboratory.
This part is applicable to fungus test of military materiel.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this part. For dated reference, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply to this part. However parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references or references with version not indicated, the latest edition of the normative document referred to applies.
GB/T 2423.16-1999 Environmental testing for electric and electronic products - Part 2: Test methods - Test J and guidance: Mold growth
GJB 150.1A-2009 Laboratory environmental test methods for military materiel - Part 1: General requirements
GJB 4239 General requirements for materiel environmental engineering
3 Purpose and application
3.1 Purpose
The purpose of this test is to evaluate the degree of mold growth in materiel and the effects of mold growth on materiel performance or use.
3.2 Application
3.2.1 This test is used to determine:
a) whether the materiel or assembly grows mold;
b) the growth rate of mold on materiel;
c) the effects of mold growth on materiel and its task completion and use safety;
d) whether the materiel can be effectively stored in the environment;
e) whether there is simple method to remove mold growth (if any).
3.2.2 This test involves highly specialized technology and contains potentially harmful microorganisms, which can be carried out only by personnel with professional technical qualifications (such as microbiologists). See GB/T 2423.16-1999 for the safety information required for this test.
3.3 Restriction
This test is not applicable to the testing of base materials, for which other material testing methods, such as soil burying, pure culture, mixed culture and plate test, shall be adopted.
4 Tailoring guidelines
4.1 Selection of test methods
4.1.1 General
Analyze the requirements of relevant technical documents, apply the results obtained by implementing GJB 4239 in the ordering process of materiel (products), determine the phase of mold growth environment in the service life of materiel, and determine whether this test is necessary according to the following environmental effects. When it is necessary to carry out this test through determination and the same test piece is used for this test and other environmental tests, the sequence of this test and other tests shall also be determined.
4.1.2 Effects of mold growth
4.1.2.1 General
As microbial degradation changes with temperature and humidity, and is closely related to the conditions in humid and hot zone and mid-latitude area, it shall be considered when designing materiel. Mold growth will change the physical properties and weaken the function or use of the materiel.
4.1.2.2 Harmful effects
The harmful effects caused by mold growth are summarized as follows:
a) direct erosion of materials. Non-mold resistant materials are vulnerable to direct erosion, because molds can decompose materials and use them as their own nutrients. This leads to the degradation of the physical properties of the materiel. Non-mold resistant materials include:
1) natural materials: plant fiber materials (wood, paper, natural fiber fabrics and ropes, etc.), animal-based and plant-based adhesives, grease, oil and many hydrocarbons, and leather;
2) synthetic materials: PVC products (products plasticized with fatty acid esters, etc.), some polyurethanes (such as polyester and some polyethers), plastics containing organic filling laminates, paints and varnishes containing components sensitive to mold.
b) indirect erosion of materials. The damage of mold resistant materials comes from indirect erosion, which occurs as follows:
1) even if the underlying material can resist the direct erosion of mold, the mold growing on the dust, grease, sweat and other pollutants deposited on its surface (formed during manufacturing or use) will cause damage to the underlying material;
2) metabolites secreted by molds (such as organic acids) will lead to metal corrosion, glass etching, coloring or degradation of plastics and other materials;
3) for molds growing on materials sensitive to direct erosion, their metabolites come into contact with adjacent mold resistant materials to cause erosion.
4.1.2.3 Physical effects
Possible physical effects are as follows:
a) electrical or electronic system: direct or indirect erosion may cause damage to the electrical or electronic system. For example, molds can form undesirable conductive paths on insulating materials, or have a negative effect on the electrical characteristics of fine adjustment circuits.
b) optical system: the damage of optical system is mainly caused by indirect erosion. Molds can have a negative effect on the light propagation energy in optical system, block the precise moving parts, make the dry surface wet and accompanied by performance degradation.
4.1.2.4 Health and aesthetic factors
Mold growth in materiel may cause physiological problems (such as allergy) or affect the beauty of materiel, which leads to users' unwillingness to use the materiel.
4.1.3 Selection of test sequence
4.1.3.1 General requirements
See GJB 150.1A-2009, 3.6.
4.1.3.2 Special requirements
Generally, this test is not suitable to be carried out on the test pieces which have undergone salt spray, sand and dust or damp heat tests in advance. If necessary, fungus test may be carried out before salt spray or sand and dust test. A large amount of accumulated salt will affect the germination and growth of molds, while sand and dust can provide nutrients for molds, so it may cause false impression on the biological sensitivity of the test piece.
Foreword i
1 Scope
2 Normative references
3 Purpose and application
3.1 Purpose
3.2 Application
3.3 Restriction
4 Tailoring guidelines
4.1 Selection of test methods
4.2 Selection of test procedures
4.3 Determination of test conditions
5 Information requirements
5.1 Information required before test
5.2 Information required during test
5.3 Information required after test
6 Test requirements
6.1 Test apparatus
6.2 Test control
6.3 Test interruption
6.4 Decontamination
7 Test process
7.1 Test preparation
7.2 Test procedures
8 Result analysis
