Pickup
Pickup turns up in 3 fields: tribology, electrotechnology, asphalt. Here is what it means to the people in each one.
Pickup in tribology
Metal transferred from one sliding surface onto another, seen as smeared lumps after adhesive wear.
Shop term for material picked up by one surface from its mating part during adhesive wear or galling: bronze smeared onto a steel shaft, aluminum on a cylinder wall, babbitt on a journal. The lumps stand proud and keep doing damage, so mechanics stone or polish them off before reassembly. Pickup is proof the lubricant film failed at some point.
"There's bronze pickup on the shaft under that bushing, polish it off and check the grease line isn't plugged."
Pickup in electrotechnology
Threshold at which a protection element starts to operate, and the moment the measured value crosses it.
Pickup is the setting of current, voltage, frequency or impedance at which a relay element starts timing toward a trip, and also the act of crossing that threshold. An overcurrent element set at 400 A pickup ignores 380 A and starts its curve at 400 A. The matching dropout or reset level is where the element returns to rest, and the gap between the two keeps the element from chattering when the measured value hovers near the setting.
"Earth fault element picked up three times overnight without tripping, something is leaking right at the edge of the pickup."
Pickup in asphalt
Mix sticking to roller tires or drums and tearing out of the mat, leaving pockmarks behind.
The problem of hot mix clinging to a pneumatic roller's tires or a steel drum and being lifted out of the surface, leaving divots and smeared texture. Cold rubber tires are the usual cause, along with sticky polymer-modified or rich mixes. Operators warm the tires by working the hottest part of the mat, fit skirts, and use a light mist of release agent, never diesel.
"Getting pickup on the rubber-tire roller, keep it on the hot mat ten minutes and let those tires warm up."