chain-float liquid-level gage

chain-float liquid-level gage

[′chān ¦flōt ′lik·wəd ¦lev·əl ‚gāj]
(engineering)
Float device to measure the level of liquid in a vessel; the float, suspended from a counterweighted chain draped over a toothed sprocket, rises or falls with the liquid level, and the chain movement turns the sprocket to position a calibrated depth-indicator.