JIAWANSHUN Oxygen Air Flow Meter 0.1-1.5LPM Gas Flow Regulator Gas Flowmeter with Copper Connector

Very nice. Smooth throttling.

I bought this rotameter to measure and control fairly low flows of carbon dioxide gas. The graduations on the scale are for oxygen flow but I can apply a factor or even recalibrate it for carbon dioxide.I like the metal barbed nozzles which easily take 1/4" thick-walled silicone tubing. The needle valve is finely made with a smooth sharp metal cone adjusted into a metal seat.It's important that these rotameters are mounted absolutely vertically for best accuracy. I designed a 3D-printed stand to hold the rotameter. However, the nuts that are needed to mount it (and are shown in the Amazon listing) were not included with the product. These are very unusual nuts with special threads and aren't locally available. So, now I have to take the time, trouble and expense to find suitable nuts online before I can mount this device. Either that or design and 3D-print some nylon nuts. I am not at all pleased about this - why can't the vendor include these difficult-to-find nuts with the product as expected in the Amazon listing?UPDATEI managed to identify the required nuts as being M10 x 1.0. It would cost me ~$10 to order a packet of these on Amazon (they're not available locally). I just printed some flanged nuts on my 3D printer out of PETG - these worked well - see photos.

As I said in another review for a separate product, I have no idea whether this product is accurate or not. However, I believe that it is and that it restricts flow to an appropriate rate for my application.I inject pure oxygen into unfermented wort prior to adding yeast to make beer. I selected this product as a replacement for another that was broken. The previous flowmeter had nylon connectors instead of sturdier metal ones.The flowmeter enables me to deliver the oxygen at steady rate, and not overly oxygenate the wort. That's why I bought the first meter. I bought this one hoping it's more permanent.I've not tried setting the output to my mouth and inhaling pure oxygen, and I'm not sure what that would even do to me. This review isn't about that.

I attached this air flow meter to my automotive smoke machine to help detect the flow in a closed system. The smoke machine helps to find leaks in a closed system. The air flow meter used in conjunction with the smoke machine helped me diagnose a leak and also helped to determine when the system had no leaks. No flow in a closed system means no leaks. Product worked great for my use. Well built and excellent price.

Not high-end metrology equipment, but for the price you pay, it's more then good. I'm very pleased with the quality.

They are not machined properly so the ball sticks! you have to tap the side every time you want a somewhat accurate reading.

It is noted to be for oxygen but I'm using it for CO2 so I doubt the flow rate numbers to be accurate, but it does allow the gas flow to be controlled. The unit has no markings as to the input and output. I had to use trial and error to make it functional. Once functional the flow was very controllable. I liked it over other flow rate controllers because of the availability of very low flow rates. I'm using it to increase the amount of CO2 for some small, enclosed plants to help them grow better.

I am using this with an oxygen concentrator and ozone set up. For the price, it works great. Definitely can handle the high pressure.