Radon Manometer U-Tube is almost equal

radon

I have a radon system in my home with a u-tube style manometer. the reading over the past year has been almost 0*. I called the serviceman who told me it was fine as long as I could hear the fan running.
*It is not a level 0- it has always been 1-2 millimeters higher on one side.

All of my neighbors meters show a drastic level difference. Is this normal?

Best Answer

A u-tube doesn't need calibration in the respect that the difference between the two scales will be twice the static suction. For convenience though, in order to read accurately from 0, it should be "calibrated", because some oil will slowly be lost over the years. Simply disconnect the tops of the tube and slide it until the oil level is even with the zero reading. Replace the connections.

How different the levels are will depend on the accuracy of the device and the size of the fan, among other factors. What's important is what was the reading when the system was new? That should have been documented after installation and posted. If the current reading is significantly different, the cause should be determined and corrected.