Testing methods and equipment for comprehensive performance of clean rooms
FILTER DETECTION
1. For the filters installed at the end of the air supply system, the scanning method is used to detect the leak in the filter installation frame and the whole section. Scanning method includes leak detector method (photometer method) and particle counter method with sampling amount less than 1 L/min. For ultrafilters, there are two methods of scanning, i. e. the fixed counter method for condensate nodules and the laser particle counter method.
2. Leak detection by leak detector
(1) Leakage filters must have measured the air flow, between 80% and 120% of the designed wind speed.
(2) When there are several filters installed on the same air supply surface, it is advisable to use the method of exposing only one filter at a time when the structure permits.
(3) When several or all filters must be exposed to aerosol at the same time, in order to make uniform mixing for all filters, it is advisable to introduce leak detection aerosol into the suction end of the fan or the branch pipe in front of these filters, and immediately measure the concentration of the upper wind side in front of the tested filters.
(4) For filters, when the logarithmic calibration of the instrument is used, the aerosol concentration on the upper side should be 104 times higher than that on the smaller scale of the instrument zui; when the leak detector is used for linear calibration, the aerosol concentration on the upper side should reach 80-100 ug/L. Leak detector should have a measurement range of 0.001-100ug/L.
3. Leakage Detection by Particle Counter Method
(1) The tested filters have measured the excess air volume and run between 80% and 120% of the designed wind speed.
(2) Measure the number of particles in the air dust on the windward side of the tested filter, whichever is greater than or equal to 0.5um, and its concentration must be greater than or equal to 3.5*104 particles/L; if the detection is more than or equal to 0.1um particles, its concentration must be greater than or equal to 3.5*106~3.5*107 particles/L.
4. When leak detection, the sampling port is placed 2-3 cm away from the surface of the filters to move at a speed of 5-20 mm/s, and the whole section, head glue and installation frame of the filters are scanned.
2. Detection of Air Volume and Velocity
1. The detection of air volume and wind speed must be carried out first. The effects of purifying air conditioning must be obtained under the designed air volume and wind speed.
2. Before testing the air volume, it is necessary to check whether the fan is running normally, whether the parts of the system are installed correctly, whether there are obstacles (such as blocked or blocked filters). All valves should be fixed in a certain opening position, and the dimensions of the tested tuyere and duct must be measured.
3. For one-way flow (laminar flow) clean rooms, the average wind speed and cross-sectional area product method are used to determine the air supply volume. The measured cross-sectional area of vertical one-way flow (laminar flow) clean rooms is 0.8 m from the ground, and the vertical cross-sectional area of horizontal one-way flow (laminar flow) clean rooms is 0.5 m from the air supply surface. The spacing of measuring points on the cross section should not be greater than 2 m, and the measuring points should be no less than 10, evenly arranged. The instrument is a hot-ball anemometer.
4. For turbulent clean rooms, the air supply volume is determined by tuyere method or duct method. See Items 6, 7 and 8, respectively.
5. For air outlets without filters, the method of Appendix 1 of the current national standard "Code for Construction and Acceptance of Ventilation and Air Conditioning Engineering" GBJ243 can be applied.
6. For air outlets with filters, auxiliary air ducts can be selected according to the type of air outlets, i.e. straight tubes with rigid plates equal to two times the length of the air outlet side, which are connected to the outside of the air outlet of the filter. On the plane of the air outlet of the auxiliary air duct, the measuring points are evenly arranged at least 6 points according to the Zui number of measuring points, and the heat is used. The spherical anemometer measures the wind speed at each point. The air volume is determined by the average net cross-section area of the tuyere cross-section.
7. For air outlets with similar diffuser plates, the air volume can be determined according to the diffusive air resistance curve (ex-factory air resistance curve or field measured air resistance curve) and the diffuser resistance (the difference between the surprise inside the orifice plate and the indoor pressure). Micro-manometer and fine pitot tube or fine rubber instead of pitot tube must be used in the measurement, but the plane of the hole must be parallel to the direction of the airflow. In addition, other methods approved by professional testing departments can also be used.
8. When the upper side of the tuyere has a long branch section and has or can be perforated, the air flow rate can be determined by the air duct method. Measuring the distance between the section and the local resistance parts, the former is not less than 3 times the diameter of the pipe or 3 times the length of the large side, while the latter is not less than 5 times the diameter or 5 times the length of the big side.
9. For rectangular ducts, the measured cross-sections are divided into several equal small sections, each of which is as close as possible to the square, the side length Zui is no less than 200 mm, and the measuring points are located in the center of the small cross-section, but the measuring points on the whole cross-section should not be less than 3. For circular air ducts, the measured cross sections should be divided into equal area circle method and the measured points should be determined.
Open holes in the outer wall of the duct for inserting a hot-ball anemometer rod or Pitot tube. When using Pitot Trust, the dynamic pressure is measured first, and then the air volume is determined by the following formula:
Q=1.29 F
Pa={(++)/n}2
Q - air volume, m3/s;
F - Pipeline cross section area,;

Pd1... Pdn - Dynamic Pressure at All Points, Pa

3. Detection of Pressure Difference
1. The measurement of static pressure difference should be carried out when all doors are closed, and should be measured outward in sequence from the room in Zui on the plane.
2. For one-way flow (laminar flow) clean rooms with cleanliness higher than 100, the number of particles in the working face height of the indoor side at 0.6m away from the door should also be measured when the door is open.
IV. Detection of Average Wind Speed and Velocity Inhomogeneity in One-way Flow (Laminar Flow) Clean Room Section
1. Measuring cross section, measuring points and measuring instruments shall comply with the provisions of Items 2 and 3 of this Appendix.
2. It is advisable to fix the anemometer on the measuring frame to avoid human interference. When the anemometer has to be measured by hand, the arm should be extended to the Zui long position so as to keep the human body away from the probe.
5. Inspection of indoor cleanliness
1. The Zui low-limit sampling points for determinating cleanliness are determined in accordance with the provisions of Schedule 6.1. Sampling times of each point are not less than 3 times, and the sampling times of each point can be different.
2. The principles of the arrangement of cleanliness measurement points are as follows:
(1) Layers can be laid out at more than 5 points, but not less than 5 points per floor.
(2) Five points or below may be arranged on the diagonal line of the 0.8m high plane above the ground, or between the two filters on the plane, or in other places where it is deemed necessary.
Note: The test of indoor cleanliness can also be carried out according to the requirements of the construction unit or design, according to the provisions of Appendix 2 of GBJ73, the current national standard.
Detection of indoor plankton and sedimentation bacteria
1. The indoor plankton and cleanliness test points can be the same. Sampling must not be carried out according to the instructions of the instrument used. Particular attention should be paid to disinfection and sterilization of the instrument before testing.
2. Petri dishes should be placed in representative places and places with minimal air disturbance when determining sedimentation bacteria.
Detection of indoor air temperature and relative humidity
1. Before the measurement of indoor air humidity and relative humidity, the purification air conditioning system shall have been in continuous operation for at least 24 hours. For places with constant temperature requirement, according to the requirements of fluctuation range of relative temperature and relative humidity, the determination should be carried out continuously for 8-48 hours, with each measurement interval not more than 30 mm.
2. According to the fluctuation range of temperature and relative humidity, appropriate instruments with sufficient precision should be selected for measurement.
3. The indoor measuring points are generally arranged in the following places:
(1) The air supply and return outlets.
(2) Representational locations in the constant temperature working area (e.g. along the periphery of process equipment or at equal distances).
(3) Room center (no constant temperature system, temperature and humidity only measured this point).
(4) Sensitive element.
All measuring points should be at the same height, 0.8m above the ground. It can also be arranged on several planes off the ground according to the size of the constant temperature zone. The distance between the measuring point and the surface of the external wall should be greater than 0.5m.
8. Detection of Indoor Noise
1. The noise measuring instrument is a sound level meter with octave analyzer. Generally, only A sound level is measured, and octave sound pressure level is measured when necessary.
2. Location of measuring points: Five points in Fig. 6-1 should be set up. If the area is 15_F, one point in the center of the room can be used. The height of measuring points is 1.1m from the ground.
IX. Detection of Illuminance
1. Indoor illumination can be measured by portable illuminometer.
2. Indoor illumination must be carried out after room temperature has stabilized and light source output has stabilized (Xin'an fluorescent lamp must have 100 hours and incandescent lamp has 10 hours of service life; old fluorescent lamp must have been lit for 15 minutes and old incandescent lamp has been lit for 5 minutes).
3. Clean room illumination only measures general illumination except special local illumination.
4. The average distance from the ground is 0.8 M. The distance between the measuring points is 1-2 M. The distance between the measuring points and the wall is 1 m (the small area room is 5 min).
10. Detection of indoor micro-vibration
1. Measure with vibration analyzer which can meet the requirement of detection accuracy.
2. The measuring points are located on the central floor of the room and on the ground where it is deemed necessary to determine the vibration position, as well as at the center of the surface of each panel (assembly cleanroom is each independent panel).
3. The amplitudes of X, Y and Z in three directions, i.e. long axis, horizontal axis and vertical axis, should be measured under normal operation and stopping operation of all indoor air-conditioning equipment. Particular attention should be paid to measuring the amplitudes at frequencies corresponding to rotating speed of rotating equipment.
INDOOR AIR FLOW PATTERN DETECTION
1. Layout of measuring points: vertical unidirectional flow (laminar flow) clean room chooses one vertical and one cross section, and one horizontal plane 0.8m and 1.5m above ground level; horizontal unidirectional flow (laminar flow) clean room chooses one vertical section and one horizontal plane of working area height, and three cross sections 0.5m away from supply wall, return air wall and the center of the room. The spacing of the measuring points on the measured surface is 0.2-1 M.
The turbulent clean room chooses one horizontal plane through the vertical and horizontal section of the representative air outlet center and the height of the working area. The distance between the measuring points on the section is 0.2 m~0.5 m, and the distance between the measuring points on the horizontal plane is 0.5~1 M. There should be a measuring point on the middle line between the two tuyeres.
2. Measuring point method: Observing and recording the flow direction of airflow point by point with smoke emitter or hanging monofilament line, and marking the flow direction on the section map with measuring point arrangement.
Detection of Streamline Parallelism
1. Observe the flow direction of air in the air supply plane with single wire. Generally, each filter corresponds to an observation point.
2. Measure the angle of air flow direction deviating from the prescribed direction with a dosage horn, and pay attention to avoid human interference.
13. Detection of self-purification time
1. This measurement must be carried out when the clean room stops running for a considerable period of time and the indoor dust concentration is close to the atmospheric dust concentration. If rapid determination is required, smoke can be emitted at that time.
2. If the concentration of atmospheric dust is taken as a benchmark, the concentration of the clean room is measured first, and the machine is started immediately. The time reading knows that the concentration reaches the low limit of zui, which is the self-purification time. If artificial (e.g. hair balan cigarettes) is used as a benchmark, the speaker will be placed at the center of the room above 1.8m above the ground to stop smoking for 1 to 2 minutes. After 1 minute, the concentration of dust will be measured at the center of the working area plane, and then the machine will be turned on. The method is the same as above.
3. The calculated self-purification time is obtained from the measured original concentration before start-up or the pollution concentration (No) 1 minute after smoke stopping, the concentration (N) when indoor reaches a stable level, and the actual ventilation times (n), and then the results are compared with the measured self-purification time.
Shandong Aide Purification Engineering Co., Ltd. devotes itself to the fields of medical purification engineering, laboratory system engineering, clean workshop system and so on. After years of development, it has accumulated rich industry experience and gained "China's 3.15 Consumer Trusted Products", "Excellent Engineers in HVAC Purification Industry in 2017" and "Enterprises in 2017". The prize of listing and listing in the stock market reform is a powerful enterprise in the clean Engineering industry. To learn more about the medical purification industry, please pay attention to the Wechat Public No. Aide-188 (Ed Purification and Oxygen Supply)