Hi Julius, First question ...

Published by

Hi Julius,

First question would be how big is the difference and is both meter has same pattern from time to time (same and consistent ups and downs between those two)? Based on my experience, the best practice of max difference allowed would be not more than +/- 10% (long explanation for this meter accuracy allowable error).

Then the following questions might come up afterwards:

1. Is the meter sizing correct? You need meter with correct flow measurement capability e.g. flow with 400-500 m3/h would need around 200-250mm meters.

2. Are the both meters share same class (old versio is class B, C, etc. and newer ISO is R100. R160, R200, etc.) as well as class 1 or 2 in “error band” since you need same sensitivity to ensure you have same measured value.

3. Have you installed the meter correctly? Like the 2D or 5D straight pipe installation of the inlet section? Most mechanical meters have short lifetime when installed near pump.

Also the degree, spaces between bends, reducers, position of meters to ensure it is full pipe, etc.

4. Have they been calibrated correctly at least within the last 2-5 years?

5. Is it possible to have transmission leak?

6. Is it possible to have backflow? Since most meters are designed to count forward not backward (it resulted uncertain errors when counting backwards).

7. Is it possible to have air measured due to wrong or incomplete installation?

I can help regarding metering theories and methods, so do not hesitate to contact me at muhammadalfalahfauzi@yahoo.com

 

Regards,

Muhammad Alfalah Fauzi