CO2 gas system FAQs

1. If Mega-Catch™ traps don’t need carbon dioxide (CO2) gas to attract mosquitoes why does the Ultra include a CO2 gas release system?

The system is designed to increase capture rates, but its use is entirely optional. Even without the system, or with the system turned off, Mega-Catch™ ULTRA traps catch mosquitoes and other biting insects.

2. How does the Ultra’s CO2 gas release system work?

Conventional traps which burn propane release CO2 in a continuous stream as part of the exhaust gases from the propane combustion process. Mega-Catch’s™ gas release system is designed to replicate a key element of human/animal respiration by releasing quantities of pure CO2 at varying rates over fixed intervals to produce a concentration gradient in the air plume emanating from the lower part of the trap. Mosquitoes use this concentration gradient to navigate their way to the trap.

3. Where do I get the CO2 from?

The Mega-Catch™ system is able to release more CO2 (and in a cleaner form) than propane burning traps by using the same cylinders as those used by the beverage industry to carbonate (put bubbles into) the likes of beers, sodas and sparkling mineral waters. CO2 gas in this form is able to be purchased from hundreds of gas supply outlets throughout North America (and the rest of the world) like PraxAir, Air Products and BOC Gases. Alternatively, look in your yellow pages under Industrial Gases or Welding Supplies.

4. How long will a CO2 cylinder last?

Quantities of CO2 gas released by the Mega-Catch™ system can be adjusted between five settings by a simple touch of the Gas Select button on the programmable timer. We recommend setting #2 or #3 for normal operation. However in preparing for an outdoor function you might wish to operate the trap on setting # 4 or #5 for a limited period. e.g. 12 hours per day for 2 or 3 days. A 20lb (9kgs) CO2 gas cylinder used at the recommended settings should last for up to four months.

5. How safe is CO2?

All animals and humans exhale CO2. Pure CO2 is safe in the small quantities released by the trap. However a build up of CO2 concentration in an enclosed space will cause asphyxia, unconsciousness and could lead to death. Therefore the Ultra trap should NEVER be operated indoors or in any other enclosed space (e.g. closed in patio) when the CO2 gas release system is in use. If a leak is detected in the system then turn off the CO2 gas immediately.

6. Do any other Mega-Catch™ traps use CO2?

CO2 Gas Upgrade Kit (sold separately) converts or 'transforms' the PRO 900 PREMIER XC to top-of-the-line ULTRA mosquito trap specifications making it Carbon Dioxide (CO2) capable. An ULTRA manual and full set of stick on badges (included in the kit) completes the transformation.

7. What size is the thread on the gas regulator and does it work worldwide?

The CO2 gas regulator included with the Pro 900 ULTRA trap has a US specification thread (CGA 320). A CO2 Gas Regulator Adaptor (sold separately) which conforms to British Standard BS341 No.8 Thread will be required if the trap is to be used outside of North America i.e. Europe, Africa and Australasia.

8. Will my CO2 cylinder be full when it arrives?

No. Transporting compressed gas cylinders is considered hazardous by most shipping companies so your cylinder will be empty and need a fill when it arrives. However, the cylinder may expel some air when the valve is first opened. This is a result of the manufacturer’s quality control testing, but it should expel for no longer than a few seconds. To find a store location where you can fill your CO2 gas cylinder use the links on our Gas Suppliers page.

9. How do you know when the CO2 Cylinder is empty?

One of the best ways to monitor the contents of the cylinder is by weight. Weigh the cylinder full then subtract the cylinder's tare (empty) weight, which is usually shown on the outside of the cylinder. The difference between the two is the weight of liquid CO2 in the cylinder. Thus when this difference has reduced by 50% then 50% of the CO2 has been used.

10. Should I Use a Gas Pressure Gauge?

Customers often want to buy a gas pressure gauge for their CO2 cylinder. The problem here is that the CO2 in the cylinder is compressed into a liquid with only the vapour pressure being measured by a gas pressure gauge. The gas pressure in the cylinder remains pretty much the same even when there is only a small amount of liquid CO2 left in the cylinder. In other words, the gas pressure does not fall linearly with the liquid CO2 level. As the remaining vapor is fully consumed, the pressure shown on the gauge will drop off very rapidly. This means that the cylinder gauge may read 900 psi until almost all the liquid CO2 has gone. That confuses a lot of people who check the gauge one day only to find that the next day the cylinder is empty. This is why we tell customers not to bother buying a gas pressure gauge for their CO2 cylinders.


For a list of CO2 gas suppliers, please see our CO2 gas suppliers page.