Recently, we’ve run into a few radar level applications that had some startup challenges, mostly because the person installing the transmitter didn’t consider how radar wave transmission would affect the level transmitter’s performance.
One trick to any installation is to reduce the number of obstructions encountered by the transmitter. But you have to take into consideration that radar waves don’t transmit in a concentric circle around the transmitter. And this can create a problem of its own.
Radar waves are emitted from the antenna cone, rod or lens in an elliptical fashion. The ellipse lines up with the conduit entries and screen for easy “aiming”.
So, if you mount the transmitter with the conduit entry and screen perpendicular to the tank wall, the ellipse intersects the tank wall, and can cause a weak signal.
If you mount a Siemens level gauge too close to a tank wall, or close to obstructions in the tank, many times a simple rotation of the level gauge will cure the problem.
Siemens radar specialists recommend installing the transmitter so the conduit runs along the line of the tank wall. This “turns” the radar signal ellipse so it doesn’t hit the wall.
If there are other tank obstructions, you may have to move the transmitter to make sure the ellipse doesn’t interfere with them. You may also be able to use the algorithms built into Siemens level instruments to help avoid (or ignore) these issues.
Lesman Instrument Company is the authorized Siemens representative in Illinois, Indiana, Missouri, Paducah KY, Wisconsin, and Michigan’s Upper Peninsula. If you are located outside that area, you can find your local sales office or get technical assistance by calling 800-365-8766.