Tech Support: Reciprocity

If the ultrasound signal is too small to make a measurement then something in the pipe or fluid is preventing the transfer of ultrasound energy from the flowmeter into the fluid.

If you experience the low signal warning when operating the Orcas Flowmeter, one option is to simply select the 'OK' button to allow the flowmeter to try again. However if you continue to receive the warning message then please continue reading this page for help troubleshooting your installation.

First, check the ultrasound signal strength icon in the upper right hand corner of the measurement view. This icon displays full bars when there is good ultrasound transfer from the flowmeter into the pipe and fluid. If no bars, then something is preventing ultrasound from transmitting into the pipe and fluid.

For immediate assistance, use the pop-up message window at the bottom of the screen to contact SoundWater.

Several reasons for low ultrasound signal are listed below:

Incorrect setup. Double check that the pipe size, material, and wall thickness are correct. The flowmeter uses these values to determine the transducer spacing, and if incorrect, the transducers will not be located properly to receive good ultrasound signal.
Confirm that both transducers are contacting the pipe. Turn the thin silver knobs clock-wise util the transducers are firmly contacting the pipe.
Confirm that there is a liberal amount of coupling gel on both transducer faces. Coupling gel fills air voids between the transducer and pipe and allows ultrasound to transfer. If insufficient coupling gel, there may be air voids between transducers and pipe, which will prevent a flow measurement.
Confirm that your flowmeter is mounted on the side of the pipe. DO NOT place the flowmeter on top of the pipe. Air pockets and gas will collect at the top of the pipe, and will prevent ultrasound transfer into the fluid.
DO NOT install the meter on partially full pipe. Ultrasound will NOT transfer through air.
DO NOT install the meter on vertical pipe where the fluid is flowing DOWN (top to bottom). This is a potential source of air pockets. Ultrasound will NOT transfer through air.
Internal corrosion will impede ultrasound transfer into the fluid. If your pipe is made of steel, and it is aging or it is in a corrosive environment, there may be internal corrosion that is impeding ultrasound transfer into the fluid. If this persists, try moving to another location on the pipe, or to a newer section of pipe. If there is opportunity for plastic or copper pipes, these materials tend to corrode less and may provide better conditions for transmitting ultrasound.
If corrosion is preventing ultrasound transfer, sometimes simply moving to another location on the pipe will allow measurement. You may randomly find a location where the corrosion is minimal and flow measurement possible.
Aeration (air pockets or gas) will prevent ultrasound transfer. Air pockets and gas will collect on the top of pipe. Be sure to install the flowmeter on the side of the pipe where air and gas will not collect.
Cavitation will prevent ultrasound transfer. Cavitation may occurs when the flow is moving at a high speed around tight corners, through valves, or through a pump. You can often hear the noticeable sound of cavitation - which sounds like gravel or rocks are flowing through the pipe. In this case, reducing the velocity of the fluid, or applying back pressure to the system may help reduce cavitaion. Another option is to find a longer straight section of pipe away from any valve, pump or elbow.
A varying ultrasound signal strength is a strong indication of an aerated fluid. The ultrassound signal strength indicator is located at the top right of the measurement view. If the icon has varying levels of signal strength, then there is most likelu a high aeration content in the fluid. Flow measureemt in highly aerated fluids is not possible. Aeration may be caused by suction of air into the pipe, or cavitation from a pump or valve.

This device complies with Part 15 of FCC Rules and Industry Canada license-exempt RSS standard(s). Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. Contains FCC ID: XDULE40-S2. CAN ICES-3(B)/NMB-3(B)