Flow meter measurement accuracy:

All meters are built in the same way and use the same formula to calculate the flow rate. There are many situations that affect the accuracy of the measurements. Trying to avoid them would increase the accuracy.

1. If there are air bubbles in the lines. Usually this might occur when using a pump to transfer water.

2. Incidents when the flow of water is too slow or too fast that is out of the measuring range. This meter has a range of 0.45 gpm and 3.7 gpm. If the flow of water is sometimes falls out of range, then it can't be counted or measured.
If you are not able to modify your setup in any way to avoid the effects of inaccuracy. You can apply a correction factor to the measurement. For example, take two to three different measurement to find the correction factor for the total count. Use a container that you can tell it has 1 gallon, 2 gallons, and 5 gallons. Use a stop watch to time how much time it takes for the meter to advance 1 gallon. If it takes 70 seconds to advance 1 gallon, then do the same test again to see if the time is about 70 seconds again. Then do the same test for 2 gallons of water. The time should be about 2 times 70 seconds or 140 seconds. If you do this test few times, and the results are the same that means you have found the correction factor. So, the correction factor in this case is 70 sec/ 60sec = 1.1666. If the meter reads 125 gallons then the actual value is about 125 * 1.1666 = 146 gallons.


Please understand most digital flow meters measures similarly. Industrial grade or commercial grade high accuracy flow meter are hundreds and thousands of dollars. Using a simple correction factor you can achieve higher accuracy regardless of your setup.