Patent ID: 7290441

Claim:
A slit rheometer for determining the viscosities of liquids comprising: a monolithic sensor plate formed from a combination of a pressure sensor membrane and a pressure sensor substrate having at least two cavities formed in one or the other or both of the pressure sensor membrane and the pressure sensor substrate, a portion of the pressure sensor membrane extending over respective cavities of the at least two cavities whereby the portions of the pressure sensor membrane extending over the respective cavities will deflect into the respective cavities upon application of pressure to the portion of the pressure sensor membrane over a respective cavity, the amount of deflection being proportional to the pressure applied to the membrane over the respective cavity, and a pressure sensor formed in each of the plurality of cavities to provide the monolithic sensor plate with a substantially smooth surface and a plurality of independent pressure sensors in the monolithic sensor plate; a channel substrate configured to form at least one flow channel therein when combined with the monolithic sensor plate with the at least one flow channel having a flow entrance and a flow exit; and each of said at least one flow channel having at least two individual pressure sensors located therein and spaced sufficiently away from the liquid entrance and the liquid exit whereby a pressure drop of fully developed flow of liquid through the at least one flow channel can be measured.