GB/T 11606.12-1989 Environmental test methods for analytical instruments - Mildew test GB/T11606.12-1989 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Environmental test methods for analytical instruments
Mold growth test
The mcthod of cnvironmental test for analytical instrumentscntsMould growth test
1 Subject content and scope of application
GB11606.12-89
This standard specifies the reagents, materials, test conditions and test methods for the mold growth test of analytical instruments (hereinafter referred to as instruments). This standard is applicable to the evaluation of the degree of growth of instruments under conditions of mold growth and the surface changes or performance effects caused by mold on them.
This standard is applicable to instruments in places where mold grows. 2 Reagents and materials
2.1 Test strains
2.1.1 The test strains listed in Table 1 shall be used. All strains shall be used at the same time. If other strains are used in the test, they must be described in detail and indicated in the test record card.
Black Xilin
aspergillus niger
Tuqu Group
aspergillus terrus
Aurcodasidium pullulans
Penicillium ochro-chloron
Scopulariopsis breuicaulis
Trichoderma viride
Table 1 Bacteria
Resistant to copper salts,
Can attack a variety of materials
Aggression to plastics
Aggression to paints and coatingswwW.bzxz.Net
Resistant to copper salts,
Aggression to plastics and fabrics
Aggression to rubber
Aggression to fiber fabrics and plastics
2.1.2 Bacteria should be placed in a test tube with agar as a culture medium. See Appendix A (Supplementary) for the culture medium for mold cultivation. 2.1.3 Bacteria should be stored in a refrigerator at 510℃. 2.1.4 The growth period of molds for preparing spore suspensions is generally 14 to 21 days, but not less than 14 days and more than 28 days. 2.1.5 The cotton plug of the culture container shall not be removed before the spore suspension is prepared. Each opened culture tube is only used to prepare one suspension. Each time a spore suspension is prepared, a freshly cultured strain must be used. Approved by the Ministry of Machinery and Electronics Industry of the People's Republic of China on March 25, 1989 24
Implemented on March 1, 1990
GB11606.12-89
2.2 Preparation of spore suspension
2.2.1 In a culture tube, add 10 mL of distilled water with 0.05% non-bactericidal spore wetting agent (such as polyhydroxyethylene oleic acid behenyl anhydride or polyhydroxyethylene stearic sorbitan) to the desired strain. 2.2.2 Carefully scrape out the spores with a flame-sterilized platinum or nickel-chromium wire loop (inoculation loop). 2.2.3 Filter the spore suspension of each strain through a thin layer of sterile glass wool into a sterile glass bottle. The mixed spore suspension needs to be centrifuged and the supernatant liquid is then poured out. Add the sediment (spores) to sterile distilled water, centrifuge and pour off the supernatant liquid. Repeat this process three times. Then pour the pure spores and 100 mL of sterile distilled water with 0.05% non-bactericidal wetting agent into a sterile glass bottle and shake to mix the spores thoroughly. 2.2.4 The spore suspension must be used on the day of preparation and must not be stored for later use. 2.3 Control paper strips || tt || 2.3.1 The control paper strips used in the test should be made of pure white filter paper. 2.3.2 The culture medium solution formula for preparing control paper strips is as follows: 0.7g
monopotassium dihydrogen phosphate (KHPO)
dipotassium hydrogen phosphate (K,HPO)
magnesium sulfate (MgsO7H,O)
sodium nitrate (NaNO,)
potassium chloride (KCI)
ferrous sulfate (FeSO,:7H,O)
steamed filling water
1000mL
2.3.3Put the paper strips into the culture medium and cover them with the above culture medium solution. Drain the paper strips before use. 2.3.4The paper strips should be prepared on the same day.
2.3.5For each batch of control paper strips, freshly prepared culture medium solution should be used. 2.4 Requirements for strains
2.4.1 The strains should be supplied by formal mycological research institutions. 2.4.2 The strains may change their ability to corrode certain materials during the continuous cultivation process. Identifying these changes requires experience in microbiology. The laboratory that supplies the test strains should ensure that the same strains that are qualified for this test method are supplied. 3 Test conditions
3.1 The temperature at each point of the effective test space of the test equipment is between 28 and 30°C, the relative humidity is greater than 90%, and the temperature change is not greater than ic/h.
3.2 In order to achieve the specified temperature and humidity values ​​in the test equipment, the air in the equipment can be forced to circulate. 3.3 If the test equipment is contaminated, it needs to be cleaned and sterilized. 4 Test methods
4.1 Initial inspection
4.1.1 The instrument should be in normal use and generally should not be cleaned. 4.1.2 According to the provisions of relevant standards, the instrument should be inspected for appearance and electrical and mechanical properties. 4.2 Test
4.2.1 The relevant standards should specify whether the instrument should be tested for performance after the appearance inspection of mold growth. If only an appearance inspection is performed, only one set of instruments is required. If a performance inspection is performed, two sets of instruments should be required. 4.2.2 The nozzle aperture used to spray the spore suspension should not be greater than 0.5mm. The sprayed suspension should be in a fine mist and sprayed onto all exposed surfaces of the test instrument.
GB11606.12--89
4.2.3 Take three control paper strips and hang them together with the test instrument, spray them with spore suspension, and expose them to the test equipment at the same time. 4.2.4 The instrument and control paper strips should be placed in the test equipment within 15 minutes after spraying. From the time they are placed in the test equipment until the test time is completed, they should not be disturbed.
4.2.5 Take out and check the control paper strips on the seventh day. If there is fungus growth, it indicates that the test conditions are suitable and the fungus is alive. If no mold growth is observed on any of the three control papers, the test is invalid and the spray test should be repeated. 4.2.6 If only an appearance inspection is performed, the instrument shall be exposed for 28 consecutive days; if a performance inspection is required, it shall be exposed for 84 consecutive days, or according to the time specified in the relevant standards.
4.2.7 The second set of test instruments for performance inspection shall be sprayed with a water solution containing only a wetting agent and no spores. The test shall be placed in another test box. If the test is conducted in the same test box, it shall be conducted after the test of the set of instruments sprayed with the spore solution and after the box has been cleaned and sterilized.
4.3 Final inspection
4.3.1 Appearance inspection
4.3.1.1 After the exposure is completed, the instruments shall be taken out and observed immediately. 4.3.1.2 After the appearance inspection is completed, the hyphae shall be carefully wiped off the surface and the physical corrosion or etching properties of the instrument surface shall be observed under a microscope (if necessary).
4.3.2 Effect of mold growth
4.3.2.1 When the test is completed, if the instrument is required to be inspected in a humid state, the humidity around the instrument shall not be allowed to drop excessively before the inspection is completed.
4.3.2.2 When the instrument is required to be inspected after recovery, the instrument shall be recovered under the specified conditions for 24 hours after being taken out, and then inspected. 4.3.2.3 After the inspection, the instrument shall still be inspected in accordance with 4.3.1.1 and 4.3.1.2. 4.3.3 Extent and grade of mold growth
The degree of mold growth shall be identified and graded in accordance with the following provisions: Grade 0 No mold growth can be observed at 50 times magnification. Grade 1 No mold growth can be seen with the naked eye, but it is very obvious at 50 times magnification. Grade 2 Mold growth is obviously visible to the naked eye, but the coverage area on the instrument surface is less than 25%. Grade 3 Mold growth is obvious, and the coverage area on the instrument surface is greater than 25%. 4.3.4 Among the three instruments, the two with the same mold growth grade shall prevail. If the long-term evaluation grade is 2 grades or more poor in concealment, the test should be repeated, and the long grade shall be based on the most serious of the three instruments. 5. Detailed rules specified in the application of this standard to relevant standards a. Whether only appearance inspection is performed;
b. The allowable mildew growth grade and the requirements for surface corrosion; c. If performance changes are to be tested, the inspection items before the test shall be specified; d. Test time;
e. The final inspection shall be carried out under the wet state or after recovery, or under both conditions. 26
A1 Chapel medium
Sodium nitrate (NaNO,)
Dipotassium hydrogen phosphate (K,HPO,)
Magnesium sulfate (MgSO,·7H,O)
Potassium chloride (KCI)
Ferrous sulfate (FeSO47H,O)
Distilled water
Sterilized Yuli
A2 Potato Glucose Agar Medium
GB11606.12--89
Appendix A
Various culture media for cultivating molds
(Supplement)
15~20g
1000mL
108kPa/30min
Wash the potatoes with water, peel them, remove the sprouts and roots, and cut them into small pieces. Weigh 200g, add 100mL of distilled water, heat and boil for 1h, then filter with double-layer gauze, add 1000mL of distilled water to the filtrate, add 20g of glucose and 20g of agar, heat and melt, then sterilize at a sterilization pressure of 59kPa for 30min.
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