wrote:
The ubiquitous 12 VDC hour meters used in the light aircraft market are
'Hobbs' hour meters.

See: http://content.honeywell.com/sensing...scorp/cat1.asp

Available at Aircraft Spruce, Sporty's etc.

My Vetus (marine diesel) control panel came with a standard Hobbs hour
meter; maybe it's the same as Volvo...?

MW

I picked up a pair of brand new surplus Volvo marine hour meters a few
years ago on Ebay, they were cheap, like $20 each. At that price, it's
worth a look. Hour meters are usually wired into an oil pressure type
of switch, this way they only record hours when the engine is running,
not when the ignition switch is in the on position.

John