Long-handled hammer for checking electrical poles before climbing - photo

[Jon]

Explanation from social media, taken with a grain of salt:

A person climbing an electrical pole taps the pole as he climbs, while listening for the sound indicating rot. The long handle is so that any rot can be found well before the lineman ascends to a rotten area of the pole.

Other methods include boring and the use of a wood density analyzer called a resistograph:



Edit: also found this pole pick.