Airflow (Volume/Velocity) and Uniformity Tests and Air Change Rate Tests
If you want to maintain your room quality (cleanliness class, uniformity of temperature & humidity, quantity of gases), you must to maintain airflow inside your room.
HVAC system is one of the important factors for every cleanroom. It can be qualified by measuring of supply airflow volume and air exchange rate to be ensuring that the circulation of airflow is high enough in cleanroom environment.
The instrument which is used to perform this test is “Airflow Hood/ Anemometer”.
HVAC system is one of the important factors for every clean room. It can be qualified by measuring of supply airflow volume and air exchange rate to be ensuring that the circulation of airflow is high enough in clean room environment. Our service also includes adjusting air supply volume to meet the design specification
HEPA filter installation leak tests can help to confirm that the final efficiency of air filter system is properly installed by verifying the absence of bypass leakage in the installations and the filters are free of defects (damage, small pinhole) and leaks (leak in the filter frame and gasket seal, leak in the filter bank framework). This could verify if any risk of contamination.
The instrument which is used to perform this test is “Aerosol Generator with PAO aerosol and Photometer”.
Cleanroom could be classified by considering on particle level at each ‘at rest’ and ‘in operation’ conditions
The objective of air cleanliness class test is to verify air cleanliness in environmental classified rooms. Table below is the acceptance standard, according to ISO14644-1: 2015.
The instrument which is used to perform this test is “Particle Counter”
Table 1 - ISO Classes of air cleanliness by particle concentration
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ISO Class number (N)
Maximum allowable concentrations (particles/m3) for particles equal to and greater than the considered sizes, shown belowa
d, e, f
1 000 000
3 520 000
35 200 000
8 320 000
a All concentrations in the table are cumulative, eg.g. for ISO class 5, the 10 200 particles shown at 0,3 μm include all particles equal to and greater than this size.
b These concentrations will lead to large air sample volumes for classification. Sequential sampling procedure may be applied; see Annex D.
c Concentration limits are not applicable in this region of the table due to very high particle concentration.
d Sampling and statistical limitations for particles in low concentrations make classification inappropriate.
e Sample collections for both particles in low concentrations and sizes greater than 1 μm make classification at this particle size inappropriate, due to potential particle losses in the sampling system.
f In order to specify this particle size in association with ISO Class 5, the macroparticle descriptor M may be adapted and used in conjunction with at least one other particle size. (See C.Z.)
g This class is only applicable for the in-operation state.
Differential air pressure test is to measure pressure difference between the cleanroom/clean area and adjacent areas. It should be in the range of user requirement specification which is specified in each room.
Under high pressure system, air flows away from the room to the place that has lower pressure. In contrast, air flows direction under low pressure environment, the airflow will be flown to the adjacent area that has more pressure level
The instrument which is used to perform this test is “Digital Manometer”.
The purpose of the airflow smoke pattern tests is to show the actual airflow pattern throughout the unidirectional cleanroom.
The test is carried out by observation or imaging of the behavior of tracer particles illuminated by the tracer particles that can be generated from materials such as fog, dry ice, de‐ionized (DI) water, sprayed or chemically generated alcohol/glycol etc. and image recording devices for recording the visualized pictures or images of tracer particles.
The test is considered to be only applicable in non‐unidirectional airflow systems because the recovery performance is a function of air re‐circulation ratio, inlet‐outlet airflow geometry, thermal conditions and the air distribution characteristics within the controlled zone.
The purpose of the test is to determine the amount of time that is necessary for non-unidirectional cleanrooms or clean spaces and their systems to reach a specified steady state cleanliness level after a brief particle generation event within the clean space.
The instrument which is used to perform this test is “Aerosol Generator with PAO aerosol and Particle Counter”.
Temperature and humidity tests are the demonstration of the capability of the HVAC system to maintain temperature and humidity levels with-in the control limits over the time period. If the temperature and humidity are too high, it can be resulting to contamination from operators’ sweat or from fungal infection. Hence, they should be adjusted at appropriate level frequently.
The instrument which is used to perform this test is “Temperature and Relative Humidity Meter”.
Temperature Mapping Studies / Temperature & Humidity Mapping Studies
The purpose of temperature mapping study / temperature and humidity mapping study is to verify that the temperature and humidity distribution within a storage area is always maintained between the desired temperature and humidity.
The instrument which is used to perform this test is “Temperature and Relative Humidity Data Logger”.