No matter what industry you're in, if your fabrication, manufacturing, or production process requires that you maintain a precise level of liquid or gas flow, you need to be able to monitor that flow easily. The best way to do that is with a thermal mass flow meter installed in the system. However, these meters are not infallible. Here are a few things you should know that can affect the accuracy of your mass flow meter readings.
Reading Too Soon
In order for the reading from your mass flow meter to be accurate, it must have reached its consistent operating temperature. This takes time, which means that you need to let the system run for a little while before you check the flow meter's reading. If the system hasn't reached its steady operating temperature, your readings may be too low or too high, depending on what's flowing through the meter.
Certain gases can produce condensation, leaving moisture accumulation inside the pipes or tubing as well as inside the meter itself. This condensation can actually interfere with the meter's ability to accurately reflect the flow through the system. Since mass flow meters rely on a mixture of temperature as well as pressure, when there's condensation on the temperature sensor, it can impede the temperature reading and disrupt the final results.
Eventually, this moisture can even lead to corrosion inside the meter. Make sure you take this into consideration if you're working with a saturated gas, and follow the meter manufacturer's recommendations for managing that moisture to ensure accurate readings.
Air Bubble Interference
In some cases, bubbles in the liquid flowing through the meter can also affect the meter's reading accuracy. Bubbles flowing through the tube allow the liquid to splash through, affecting the vibration of the tubes. This can alter the readings from the sensor, resulting in inaccuracies.
Any particles that have been introduced or generated within the system can also wreak havoc on your flow meter's readings. Particles can accumulate on the sensors of the meter, resulting in a residue that prevents the sensors from accurately responding to the environment. You may find that your meter's readings are too low in these situations.
The meter's sensors will need to be thoroughly cleaned and particles removed from the system whenever possible. If the particles are a component of the material flowing through the system, you'll need to maintain the meter on a more frequent basis to ensure reading accuracy.