Dust-proof test box> is a kind of equipment for dust-proofing products. Now some products have strict requirements on the use environment, so they will choose to use dust-proof box> for dust-proofing test. We will now start the following research and analysis on the dustproof test box.
1. Working requirements of dustproof test chamber>
1. Dust blowing
It is used to study the adaptability of equipment to dust blowing (≤149μm). Test temperature: the working high temperature or storage high temperature obtained from the temperature response of the specimen in the high temperature test (GJB 150.3A); humidity ≤ 30%.
2. Sand blowing
It is used to study the adaptability of equipment to sand blowing (150μm-850μm). Test temperature: the working high temperature or storage high temperature obtained from the temperature response of the specimen in the high temperature test (GJB 150.3A); humidity ≤ 30%.
3. Dust reduction
Used to study the effect of dust fall (≤105 μm) on equipment (usually electrical equipment) in covered or enclosed areas where dust can accumulate for a long time (such as offices, laboratories, storage rooms and tents) with little air movement. Influence. Dust fall can also affect the cooling of equipment that has accumulated dust on the top surface. The dust drop test is also used to check the quality of the air filter at the inlet of the air pollution sampler used outdoors. Test temperature: 23℃±2℃, humidity ≤30%.
2. Temperature index of dustproof test chamber>
1. Temperature uniformity: It is the value of the difference between the average temperature of any two points in the working space within any time interval after the temperature is stabilized. This index can assess the core technology of the industry better than the temperature deviation index below, so many companies' dustproof test chamber manuals and technical solutions deliberately hide this item.
2. Temperature deviation: After the temperature is stabilized, within any time interval, the difference between the average temperature of the center temperature of the equipment working space and the average temperature of other points in the working space. AlthoughThe old and new standards have the same definition and name for this indicator, but the detection has been changed. The new standard is more practical and stricter, but the assessment time is shorter.
3. Dust-proof box> temperature change rate: This is an indicator for assessing the industrial configuration capacity. The forms given by the manufacturer are also varied, including heating and cooling speed, heating and cooling time, heating and cooling capacity, etc. The cooling range is also not uniform.
4. Temperature range: refers to the limit temperature that the industrial studio can tolerate and/or reach. It usually contains the concept of constant control, and its equipment should be the extreme value that can run stably for a relatively long time. Typical temperature ranges include extreme high temperatures and extreme low temperatures.
5. The index of temperature fluctuation is also called temperature stability. After the temperature is stabilized, within a given time interval, the difference between the high temperature and low temperature at any point in the dustproof test chamber> working space . There is a small difference here: the working space is not the studio, it is a space that is about 1/10 of the length of the studio minus the respective sides of the box wall. This indicator assesses the control technology of the industry.
3. Daily maintenance of dustproof test chamber>
1. To prevent dust from entering the box, cover the plastic cover after use;
2. The transmission mechanism must be refueled regularly, and the reducer must be refueled with clean gear oil;
3. Dust-proof test chamber> is exposed to the environment for a long time, and dust will accumulate on the outer surface. In order to ensure that the equipment does not affect the indoor appearance and cleanliness, and slow down the aging of the equipment, please clean the outer surface of the equipment once a week. Corrosive cleaning agents are prohibited when cleaning the product;
4. If the electrical components in the control cabinet collect a lot of dust, it will cause failure, and dust removal should be carried out at least once every six months. Method: first turn off the main power switch, open the cover of the power distribution room, use a vacuum cleaner (or a soft brush) to clean the dust on the electrical parts, cover the cover of the power distribution room, and tighten the screws.
5. When the machine is not started for a long time, the program in the computer may not work. Please start the machine once every half a year to replenish the backup battery. The power-on time is 8 hours;
6. When moving the dustproof box>, avoid dropping, impacting, scratching, twisting, extreme vibration and extrusion;
7. Avoid placing heavy objects on the equipment and avoid tilting the equipment;
8. Prohibition of contact with chemicals;
9. Keep the laboratory in a dry environment.
Fourth, Dust-proof test chamber dust blowing procedures>
1. According to the provisions of the technical documents, adjust the temperature of the test section to the standard atmospheric condition, and adjust the air velocity to the required value. Adjust the relative humidity value of the test section to less than 30%, and maintain this humidity value throughout the test procedure.
2. Adjust the dustThe control device makes the dust concentration reach 10.6g/m3±7g/m3.
3. Unless otherwise specified, keep the conditions achieved in 1 and 2 for at least 6 hours. If necessary, periodically reorient the specimen so that other vulnerable surfaces are exposed to the dust flow.
4. Stop the dust supply. Reduce the wind speed of the test section to about 1.5m/s, and adjust the temperature of the test section to the specified temperature of the test, or other values determined in the technical documentation.
5. After the test temperature is stable, keep the condition of 4 for 1 hour.
6. Adjust the wind speed to the speed used in 1, and restart the dust supply to maintain the dust concentration in 2.
7. Continue the test for at least 6 hours or according to other regulations. If necessary, run the specimens as specified in the technical file.
8. Return the sample to standard atmospheric conditions and allow the dust to fall.
9. Remove the dust accumulated on the sample by brushing, wiping or shaking. Care shall be taken so as not to introduce additional dust or to disturb any dust which may have already entered the specimen. Dust shall not be removed by blowing or vacuum cleaning, unless these methods are the same as those used in actual use.
10. Carry out work inspection according to technical documents, and record the inspection results.
11. Check the sample to determine whether there is dust penetration, pay special attention to bearings, grease seals, lubricating parts, filters, ventilation, etc. Record the inspection results.
5. Wind speed requirements for dustproof test chamber>
1. The requirements for wind speed in the dust blowing test, because the weight of the dust is different, it should be determined according to the actual requirements. The wind speed should be >1.5m/s. If the simulation is sand and dust in the desert, because of its heavy weight, the wind speed should be >8.9m/s, or higher. Of course, if there are other sizes, please refer to them.
2. For the requirements of wind speed in the dust fall test, it is enough to ensure that the disperse test piece inside the test chamber is not stained with dust. To achieve this goal, the wind speed should be less than 0.2m/s.
3. For the sand blowing test, the basic requirement to meet the wind speed of the sand blowing test is that the wind speed is in the middle of 18m/s~29m/s. It should be noted that in addition to considering the wind speed, the distance between the sand injection inlet and the test piece should also be considered. If it is too close, it will be blown away; if it is too far, it will not reach the sand collision speed required by the test, which is generally 3m, but if the wind speed is normal and the desired collision speed can be achieved at a short distance, it is also possible. In the wind speed range required by this test, large wind speeds are relatively rare, and gusts like 29m/s are rarely used in the test.
6. Matters needing attention in the use of dustproof test chamber>
1. It is strictly forbidden to use a power supply outside the allowable voltage range and specified frequency, and the power supply must be well grounded.
2,Do not use if the power cord or plug is damaged, or if the plug does not fit securely into the outlet.
3. Be careful not to damage the power cord.
4. Please do not open the case door when there is no failure, or when checking and adjusting, and do not let foreign objects enter the case.
5. If any failure or damage occurs during work, immediately press the emergency stop switch or cut off the power supply.
6. Do not hit the glass door with hard objects.
7. Do not scratch the device casing with hard objects, and do not wipe the device casing with corrosive liquids.
8. The selection of talcum powder should comply with various regulations on human health and safety. After the test is completed, wait for the dust to settle completely before opening the door to take out the workpiece.
9. The operator needs to wear a mask to avoid inhaling dust into the human body.
10. When starting up, check whether the door is closed properly.
11. The control panel is touch-operated, and only finger buttons are allowed. Fingernails, sharp objects, metal products, etc. cannot be used to click.