I entered the wrong tube length (or length above concrete) for one or more tubes in the CHAMP. Is there any way of correcting that?

Yes, but this correction cannot be made on the CHAMP; you have to transfer the data to a computer and read the data with the CHA.exe software application. For instructions on how to make the change, please click here. However, keep in mind that this operation will not always be fully successful, and requires extra effort and care, so it is more efficient that you carefully always measure correctly and then enter the correct lengths in the field prior to collecting data.