Consibio provides several solutions for measuring water level and flow. You get the most precise flow readings if you combine a level measurement with a direct measurement of the flow velocity to provide a full non-contact area-velocity flow meter setup with Consibio's Advanced Flow solution.
The solution relies on two different radars:
- A level radar that measures the distance from the installation point to the water surface.
- A surface velocity radar that measures the flow velocity of the water surface.
While the setup is usually deploy and forget, there can be certain locations where you want to maximize the accuracy or where the surface velocity is measurably different from the average velocity in the channel due to the local geometries and flow conditions.
In those cases, you want to calibrate the velocity reading to get the highest flow accuracy possible. The steps required to do that is outlined below.
Step-by-step
To calibrate the velocity reading, you have to:
- 1. Go to the site
- 2. Perform a reference-measurement
- 3. Make the Logger send the latest value to Consibio Cloud
- 4. Enter the calibration in Consibio Cloud:
1. Go to the site
Go to the site of the flow installation and bring a smartphone, an iPad or a laptop so you can access Consibio Cloud on the go.
2. Perform a reference-measurement
Next, you need to perform a reference measurement of the current velocity in the water stream using a handheld velocity meter. Any submersible water velocity meter can be used for this, but remember that the accuracy of the handheld instrument directly affects the accuracy of the calibration.
An example of an appropriate velocity meter is the Flow Probe from YSI.
If possible, take the average of multiple readings at different depths and different places in the stream to account for non-planar velocity profiles. Some handheld instruments (like the Flow Probe) can do this averaging for you automatically.
Note down this reading - you need it in a short while.
3. Make the Logger send the latest value to Consibio Cloud
Now we need to make the Logger perform a measurement and send it to Consibio Cloud immediately, such that we get our reference measurement and actual measurement without a significant difference in time.
To do that, activate Deploy Mode on the Logger:
- Press “Restart” shortly
-
Hold “Deploy Mode” for approximately 5s.
When the LEDs flash quickly one at a time in a repeating pattern, Deploy mode is activated.
For the next 1 hour, the device will make a measurement every 30s and transmit every 5mins.
After 1 hour, it will revert to the transmission and measurement interval configured in Consibio Cloud.
If the Logger has not connected on this physical site before, opening the connection can take some minutes on the first attempt.
4. Enter the calibration in Consibio Cloud:
Open Consibio Cloud from a smartphone, iPad or laptop by going to https://consibio.cloud and open the project you use for this setup. (remember, you can Install Consibio Cloud as an App).
Go to the "Elements" tab, and find the velocity element for this location. If you have many elements in this project, use the search filters in the top and search for "Velocity" or similar.
Click on the element, and scroll to bottom and click "Calibrate":
Click on "Enter calibration points":
Under “Measured value”, the most recent value will automatically show up:
If you have just forced the Logger to transmit the latest value (step 1), it can take a couple of minutes, before it connects successfully depending on local coverage. Until then, the latest value might be several hours ago (like shown above). Wait a minute and click the “Update” button to pull the latest value.
Under “Calibrated value”, enter the averaged velocity value you measured in step 2).
Then, click “Confirm 1-point linear calibration”.
That's it! The calibration has now been saved in Consibio Cloud. The next time, the Logger connects, it will get this new calibration and use it from then on.
Pro tip: When the calibration has been saved, force the Logger to transmit again by holding the WAKE button. In this way, it will receive the new calibration immediately.
If you have any questions, don't hesitate to reach out to us at support@consibio.com