Understanding Oxygen Flow Meter Measurement: A Guide to Reading

Sep 7, 2023

Understanding Oxygen Flow Meter Measurement: A Guide to Reading

An oxygen flow meter is a machine that measures the flow rate of various medical gases. A flow meter is constructed from a tapered tube made from glass or plastic and contains a small, free-moving indicator such as a ball or bobbin. When valves are open, the gas moves through the flow meter and causes the ball or bobbin to float. But how exactly do you read the oxygen flow measurement? We’ve got the answer below.

How to read an oxygen flow meter

Oxygen flow meters are a relatively simple device that consists of a tube through which gas passes. As the gas moves through the tube, it lifts the indicator until the pressure of the gas is equal to the pressure above the indicator. A numbered scale allows the caregiver to determine the flow rate of oxygen.

There are a variety of flow meter options available but one of the most common and most accurate are bobbin flow meters. These flow meters contain a small, pointed bobbin or float. This design optimises gas flow around the indicator.

When learning how to read this type of oxygen flow meter, simply measure from the top of the bobbin. Draw a horizontal line from the top of the bobbin to the scale located on or beside the flow meter tube. The number on the scale will indicate the flow rate.

Learning how to read the oxygen flow meter ball is similar to reading the bobbin. However, while bobbin flow meters are designed to be read at the top, ball flow meter measurements should be taken from the middle of the ball.

Oxygen flow meter measurements tips

  • Medical gases vary in terms of density and viscosity and so will require a unique flow meter. Flow meter units intended for one gas should not be used for another type of gas.
  • You may be able to fix a broken flow meter, but you must use the correct ball or bobbin if you opt to repair rather than replace it. Ensure you use an authorised repairer for maintenance of this equipment to ensure correct functionality.
  • The flow meter must remain vertical during use. Otherwise, the bobbin or ball will not give an accurate measurement of flow rates.
  • There are several different types of indicators that can be used in flow meters, including:
    • Bobbins
    • Balls
    • Rotating indicators (Floats with an upper head — or rim — larger than the rest of the indicator. These floats often have slots or grooves cut into the edge, which causes the indicator to spin as the gas is flowing)
    • Non-rotating H float (Float that looks like a capital H tipped on its side)
  • Flow meters are generally less accurate at low flows and offer more precise when serviced regularly.

Flow meter care

Now that you know how to read your oxygen flow meter, you’ll want to ensure accurate measurements by caring for your equipment. It’s vital to keep the flow meter in working condition to ensure that the patient receives safe and effective oxygen therapy. To care for your flow meter properly:

  • Ensure the bobbin or ball is floating freely. Static electricity or dirt may cause the indicator to stick to the side of the tube and result in an inaccurate reading.
  • Ensure that all medical gas equipment is serviced regularly and routinely checked thoroughly for damage. Replace any worn or damaged elements immediately.
  • Keep the inside of the flow meter clear from moisture, dust, dirt, and lubricants or oils.
  • Clean the outside surface of the flow meter with a cloth and mild detergent. Do not use caustic cleaning agents.
  • Do not drop the flow meter — doing so might result in irreparable damage.
  • Never immerse the flow meter in water or other liquids.

Mega Medical: Australia’s online medical supply provider

Whether you need to replace a flow meter, book in a routine maintenance check, or restock air resuscitation masks or other consumables, Mega Medical is the place to go. As one of the leading providers of high-quality medical supplies, we’re proud to offer an extensive range of the tools and equipment that caregivers need to ensure their patient’s comfort and health.

If you enjoyed learning how to read the flow meter, visit our blog for other useful guides and information regarding our range of medical items.

Reach out on 1300 881 824 or send us a message to order your supplies or book a service today.