Liquid Chromatograph Mass Spectrometer - sswelm/KSPInterstellar GitHub Wiki

The Liquid Chromatograph Mass Spectrometer. or LC/MS, is used to identify liquid samples by ionizing a small atomized sample injected into the device often times by laser excitation, accelerating the ions through a known electric field field strength, chamber of known length and recording the collision times against a charge detection plate. In doing so, it can determine charge/mass ratio, which can be used to identify the composition of complex samples.

The LC/MS has no science experiement associated with it. It is used to determine the composition of oceans when the vessel is splashed down in water. It will display a readout window of relative composition data when activated. The only places it will work currently are Kerbin, Laythe and Eve, as they are the only planetary bodies in the stock game that have bodies of water.

Note that this device is of limited use because ocean composition on a body is homogeneous, unlike land based resources, which have varying concentrations across their surface.