{"id":5660,"date":"2022-10-08T23:58:00","date_gmt":"2022-10-08T23:58:00","guid":{"rendered":"https:\/\/www.lighthousetest.com\/zh\/?post_type=knowledge-center&p=5660"},"modified":"2022-10-25T18:26:28","modified_gmt":"2022-10-25T18:26:28","slug":"the-basics-of-gas-sampling-in-a-cleanroom-627","status":"publish","type":"knowledge-center","link":"https:\/\/www.golighthouse.com\/zh\/blog\/the-basics-of-gas-sampling-in-a-cleanroom-627\/","title":{"rendered":"The Basics Of Gas Sampling In A Cleanroom"},"content":{"rendered":"\t\t
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It is no mystery that cleanrooms need to be, well, clean. From the surfaces and tools to the air in the cleanroom, everything needs to remain at a certain level of cleanliness depending on the cleanroom\u2019s classification and application. Those criteria extend to the compressed gasses used in cleanrooms, as well, like oxygen, hydrogen, methane, nitrous oxide, etc.<\/p>

These compressed gasses need to be sampled and monitored just like the air in your cleanroom. GMP requires this testing, as well as other regulatory bodies. For instance, ISO 8573 outlines requirements for air samplers or particle counters and the contamination values for the different classifications of cleanrooms.<\/p>

When deciding what tool to use for gas sampling, you should first understand your needs and then the benefits presented by either a particle counter or an air sampler. Depending on your cleanroom\u2019s classification and application, either tool presents a valid option.<\/p>

Using Particle Counters For Gas Sampling<\/strong><\/p>

When using a particle counter for gas sampling, you will also need to use a High Pressure Diffuser (HPD). This is a tool that connects the gas line to the particle counter intake. It diffuses the compressed gas so as to prevent damage to the delicate sensor and laser diode. There are two primary types of HPDs: Vented Return HPDs and Ported Exhaust HPDs.<\/p>

Which HPD you choose depends on the type of compressed gas you are using. Vented Return HPDs vents the gas back into the environment, whereas Ported Exhaust HPDs releases the air outside of the environment. This is useful for unsafe gasses, such as flammable ones if open flames are present in the environment.<\/p>

The HPD does more than venting the gas and protecting the sensitive interior of the particle counter. It also ensures isokinetic sampling<\/a> by decreasing the flowrate of the gas to match that of the particle counter. To verify the system is set up correctly and results are accurate, the flow rate should be the same through the HDP and the particle counter.<\/p>

With the right pressure, the particle counter is able to sustain the right air flow. The table below outlines the correct HPD adaptor adjustment based on the inlet pressure of the compressed gas to be sampled to maintain ideal flow into the particle counter for accurate sampling.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Using Active Air Samplers For Gas Sampling<\/h2>

If you use the right Active Air Sampler, it can eliminate the need for attachments like an HDP. For example, the ActiveCount100H makes gas sampling a breeze.<\/p>

You\u2019ll want to simply start with a new Petri dish, free of agar. Once the fan is blowing, you\u2019ll attach the gas sampler snugly to the sampling head. Next, you\u2019ll simply adjust the flow rate to optimize it for gas sampling. The ActiveCount100H makes this simple to do with easy to read indicators. And just like that, you\u2019re ready to start gas sampling!<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Choosing Your Gas Sampling Equipment<\/span><\/h2>

Depending on your cleanroom\u2019s application and classification, you\u2019ll need to monitor for different sizes of particles. This will impact the equipment you should use. For many cleanrooms, portable particle counters are already in use and readily available, making for a multi-use tool and investment. Whether you choose to use an active air sampler or a portable particle counter, you should ensure you\u2019re choosing a powerful, top-of-the-line, versatile tool with manufacturer support.<\/span><\/p>

When choosing an active air sample, we recommend looking for the following attributes:<\/span><\/p>