I have only ever used calibrate at the start of a relevant centreline, so have not tested Tarquin's suggestion, but I'm sure you have Tarquin :)
Indeed. I used it while surveying a sump, pointing the laser into it to measure the depth, calibrating the length for the refractive index of the water to get the actual depth (and yes, I did all the maths to work out how much was in water and how much was in air, because of course I did), rather than what the Disto thought it was. I interleaved the data with the relevant: 1 2 3.4 56 -7.89 calibrate tape 0 0.96 2 3 7.8 90.1 -78.9 calibrate tape 0 1 2 4 1.2 34 5.6 Part way through the data, one calibrate command sets it to a new value, and then later another sets it back to defaults ("0 1" in the case of tape). Other centreline blocks already reset to default without needing to be explicitly stated, so they are not affected. (And for those who care, yes, of course the refraction also altered the clinometer readings, but I was only using them to splay the walls and measure the deep spots, so I kept it mostly vertical, and pretended not to care about the imperfections!) Sent from my phone earlier, so I couldn't check the specifics.