How to Read an Oxygen Flow Meter

Oxygen tanks are used in hospitals, scuba gear, firefighter support systems and for home health care. A flow meter is attached to almost all oxygen tanks 1. Flow meters usually come in a circular design, similar to an outdoor thermometer, or a vertical design, like a first aid kit thermometer. Once you get the hang of it, they are as easy to read as a thermometer. If you care for someone who needs a home oxygen tank, you need to know how to read the flow meter.

Open the valve on the tank to begin oxygen flow. This will cause the arrow to move on a circular meter. It will cause the little ball, or bobbin, to rise on a vertical meter.

Check the number at which the arrow points or to which the ball or bobbin rises. This tells you how many liters of oxygen per minute are flowing from the tank.

Adjust the valve on the tank to reach the level of oxygen flow you want. Loosen the valve to increase flow or tighten it to reduce flow.


If your flow meter uses a bobbin, the correct reading is the number aligned with the top of it.


A vertical meter must remain in a vertical position for a proper readout.

Check the meter frequently for cracks or dirt. Either could cause a false reading.