Klydonograph

[ klahy-don-uh-graf, -grahf ]
/ klaɪˈdɒn əˌgræf, -ˌgrɑf /

Trademark.

a brand name for an instrument that photographically records a surge of voltage, as in a power line.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019