Moisture meter and water heater leaks

I have a pin type moisture meter that I’ve inserted probes at the bottom rim of some older water heaters that have had very high moisture readings, although there were no telltale signs of leakage. I then report that water heater had high moisture content and may be failing & plumber should further investigate and use corrective action as necessary.

Anyone else do this? What about you IR people - Can you distinguish WH leaks with no other signs of obvious leakage?

Here’s a link showing bottom rim & where I’m talking about:

As always, thanks in advance.

FYI - Above link is really detailed, impressive, & educational - may want to check it all out & save in your files.

I don’t understand the concept of using a moisture meter on a water heater. If you see water outside the shell it’s leaking. If the shell is corroded, it is probably leaking and should be replaced. Otherwise, no leaks to document.

electrical resistance moisture meters will alert, false positive, when pins or nondestructive sensor contacts many metal building materials

surrounding non-metallic building materials can be tested with accurate results

ir can show an exception, difference in palette coloration or temperature, but these should be confirmed or dismissed with further moisture meter evaluation

Based on the root cause for this leaky hot water heater, the condition is generally rapidly sorted out by securing all of the screws that keep the pressing assistance valve, or it may trigger water boiler replacement.