Thailand's Premier SCBA & SCUBA diving equipment service centre.
Air quality testing
CGA grade D
CGA grade E
Description of contaminants.
HSE document on air quality testing
If your divers are getting headaches or feeling nauseous after a long dive, it could be methane, elevated carbon dioxide, carbon monoxide, or the breakdown products of overheated compressors contaminating the air. It is not uncommon for gas leaks or restaurant exhaust to end up in the intake of compressor systems where it will concentrate (filters will not purify it). Carbon Dioxide can also build up in the air, but for an entirely different reason. And then, of course, we have the possibility of oil mist or oil oxidation products. You can't detect them when the air goes from the compressor or air bank right into the SCUBA cylinders. The point is, without a test of some sort, you will never know what is in the air;
The Professional Association of Diving Instructors (PADI) requires that all PADI Dive Centers test their compressed air quarterly according to CGA Grade E air specifications.
If diving is your business then the safety of the breathing air you are providing to your customers is just another concern that you can do with out. Leave that to us!
Easytek can easily test your air to CGA grade D, E or EN12021 with our simple and inexpensive testing sytem.
Air analysis can have a significant effect on your business, even if you are not required to do it. When you post our Air Quality Certificate at your filling station, you are advertising your commitment to a quality service.
The feeling of trust can begin or end right there.
- We supply you with a pre-cleaned and prepared cylinder to fill with your air test sample. Then carry out the following steps
- Confirm your compressor output filter cartridge is within the recomended running hours, oil level checked, input filter checked, etc
- Start the compressor as normally and carry out the normal startup running checks - purge the condensate towers, confirm correct PMV and safety valve operation, etc.
- Run the compressor for a few minutes with the cylinder filling adapters open (air hissing into the atmosphere) to dry out any residual moiture left in the filling hoses.
- Connect a filling hose to the test sample cylinder and fill it to 200bars.
- Once the test cylinder has reached 200bars, close the test cylinder cylinder valve and shut down the compressor normally.
- Return the test cylinder to Easytek
Payment, Shipping, Measurement, Admin process
- Bank transfer the remote air test fee of THB3,500 to our Bank account.
- We EMS the test cylinder to you on receipt of funds transfer confirmation
- You fill the cylinder with your test gas
- You return the cylinder to us by EMS
- We carry out the Air analysis fo your test gas sample on receipt of your cylinder.
- We email you the test results (usualy within 24 hours of cylinder receipt)
- We EMS you the physical test certificate to your company.
You may chose to collect and return the cylinder to us yourself to expedite testing.
You can also witness the air quality testing process if you chose - this takes a few hours..
Test Cylinder Physical data (attached)
Type:- Luxfer S06
Dimensions:- 3.25 x 14 inch
Working pressure:- 3000psi/207bars
Test Volume:- 6 cubic foot/170 Liter
Fill Connector:- Standard American A-Clamp/Yoke Valve(photo attached)
Cylinder prefil state:- Pre-dried with EN12021 Divers breathing air at 1bar abs.
Technical Information relating to the compressor filtration system requirements to produce EN12021 divers breathing quality air can be found online at:
The air tester uses the Draeger-Tubes® to test the air quality of the sample cylinder. Each tube contains chemicals that react with a specific compound (such as hydrocarbons, moisture, carbon monoxide, and so on) to form a color or stain inside the tube. The concentration of the contaminant is determined by the length of the stain (or the intensity of a patch of color) after passing a known volume of air through it.
Draeger-Tubes® are glass vials filled with a chemical reagent that reacts to a specific chemical or family of chemicals. A calibrated sample of air is drawn through the tube with the Hamworthy air tester. If the targeted chemical(s) is present the reagent in the tube changes colour and the length of the colour change typically indicates the measured concentration. The Draeger-Tube® System is the world's most popular form of gas detection.
Air quality standards
|Carbon Dioxide||1000 ppm|
|Oil / Particles||5mg/m3|
|Oil / Particles||5mg/m3|
|Carbon Monoxide||< 3ppm|
|Dew Point||see chart below|
CO2 levels in Air up to 10,000 ppm are not considered hazardous. However, compressed breathing gas with CO2 levels that are at the high end of this range can create problems while SCUBA diving. High CO2 levels in SCUBA diving can produce many of the milder symptoms of Carbon Monoxide poisoning, such as headaches and dizziness. In addition, high CO2 levels increase breathing rates and increase gas consumption during diving.
Carbon Monoxide (CO), a colorless, odorless gas, ranks as the most dangerous compressed breathing gas contaminant. Headaches, dizziness, unconsciousness, or death can occur from exposure to even slightly elevated CO levels.
Inhaling hydrocarbon based oils from improperly maintained oil lubricated compressors can cause a serious inflammation of the lungs, known as lipoid pneumonia. Inhaling very fine particulate matter has been associated with respiratory and cardiac problems, infections and asthma attacks. Particulates also clog inlet filters of SCUBA regulator first stages, causing poor performance and increased breathing effort. The build up of oils and particulates in a SCUBA cylinder can provide the fuel and source of ignition for combustion inside the cylinder during filling, introducing the possibility of severe contamination.
SCUBA breathing gases should be as dry as possible. As the temperature of a gas decreases, its ability to hold water as a vapor decreases. When the breathing gas reaches the dew point temperature, water vapor condenses into a liquid (water) or, if the temperature is low enough, solid (ice crystals). SCUBA gases must be dry enough to prevent malfunctions due to internal condensation or icing buildup caused by expansion cooling as the gas passes through regulators. Higher moisture content in gases at the pressures in SCUBA cylinders can also very significantly accelerate corrosion of the cylinder.
TOTAL VOLOTILE HYDROCARBON CONTENT (T.H.C).
Breathing hydrocarbons can interfere with oxygen intake, and short-term exposures are associated with mucus membrane irritation, nausea, vomiting, diarrhea, and confusion.
Several thousand types of organic gases and vapors can potentially be present in Air. Volatile organic contaminants can be manmade (e.g., gasoline vapor, exhaust fumes, cleaning solvents) or from natural biological activities (e.g., methane from organic decay). They are measured as a group described as a Total Volatile Hydrocarbon Content (TVHC).
Because the sensory response of the human nose is highly variable and extremely sensitive to certain odors, evaluation of odor is highly subjective. Very clean breathing gases will sometimes be said to have an odor, when actually the smell of the sample is merely "different" than the ambient odors of the surrounding environment. Although not harmful, the presence of a pronounced odor in a breathing gas is unsatisfactory.