You searched for: “algometer
algometer, algesimeter (s) (noun), algometers; algesimeters (pl)
An instrument that purports to measure sensitiveness to pain in terms of amount of pressure exerted on the skin: Dr. Dawson used an algometer on Mr. Smith's foot in order to assess the intensity of pain as part of his patient's check-up.
Weeds are a pain in the grass.
—Slogan on an invoice from a Pennsylvania tree-and-lawn-spraying service.