Wild_Bill wrote:
You're right about digital temperature readouts for soldering iron tip
temps.. Depending upon the quality of the controller design, the readout may
only be accurate for a (small) portion of the span of the temp control.

One can periodically check the tip temp at various settings with a
thermocouple, in the way that routine calibrations are required in some
areas of assembly work.
The tip temp will show a lower temperature with the thermocouple readout if
the tip is basically dry.
A decent sized blob of solder on the tip will improve the heat transfer to
the thermocouple junction, for a more stable and accurate reading.

FWIW, I stopped using dampened sponge tip cleaners a number of years ago,
and instead use the kitchen pot scrubber type of tip cleaner.
The damp sponges tend to drop the tip temp quite a bit, and I suspect the
thermal shock probably impacts the service life of the iron clad/plated

I switched too to the scubby pad in a metal cup tip cleaners too (Hakko
599B).

The only thing I still use the wet sponge for is cooling down a tip after
tinning it when the irons gets shut down. Big chisel tips can take a while
to cool off.