We have a year of SL2 data from an HST-WSBL Lowrance transducer that we have developed into depth and Hardness charts based on E2. We normalized the E2 data by scaling each track so it is consistent with prior tracks over the same area. We now need to replace the original transducer with another HST-WSBL. They appear physically identical. Can we expect the Hardness data from the replacement sensor to be consistent with our existing data?

It's hard to say. Typically it is tough to get hardness values to align nicely between different transducers, so I'm afraid that all I can suggest is that you give it a try and play with the scale and offset parameters to see if you can get a decent match.

Hi msacarny!
For couple of years I have been collecting hardness data with 4 different fishfinders and transducers. The data is never the same but it is not too different eather. You can always adjust it (scale and offset) and do your best to get a decent map. The really hard areas are always going to stick out!

One could argue that HST-WSBL is not a good choice at all when looking foe bottom composition due to its wide coneangle. ;)

As riba said, you will get sligthly different values from two ducers, even if if they are the same model. It all comes down to how precise you want your data to be, but with HST-WSBL it will be a bit off anyway.