Handling Installation Issues of Non-Standard Parshall Flumes in Ultrasonic Open Channel Flow Meters
When using an ultrasonic open channel flow meter, the installation of the flume must also follow certain standards. Improper installation can cause various problems and directly affect the measurement results of the open channel flow meter.
The following are actual problems encountered by our customer during the use of a self-installed non-standard Parshall flume, along with the subsequent solutions.
Causes: Non-standard Parshall flume (no throat section), inverted inlet and outlet, upstream channel too short (only 1m distance from the outlet to the flume, with a certain slope causing the water flow to be too rapid and failing to form free flow)
The horizontal bar below the probe is approximately 5cm away from the vertical projection directly beneath the probe, and the vertical distance from the probe to the horizontal bar is about 37cm
Solution:
We explained to the customer that the Parshall flume needs to be re-fabricated and properly installed (lengthen the channel, form free flow before water enters the measuring weir flume, and ensure no obstacles within a 30cm diameter range directly below the probe).
Temporary measures:
Place a brick at the outlet, 0.6m away from the Parshall flume inlet, to stabilize the water flow; change the instrument probe type to 1, and adjust the short gate threshold value to 75 to reduce the influence of the horizontal bar on measurement.
If you have any questions during the use of ultrasonic open channel flow meters, please feel free to call our hotline: 0591-28082552 Fuzhou Dayu Electronic Technology Co., Ltd. will serve you wholeheartedly!