Refractometer

Claim 2

The refractometer of claim 2 including a mounting plate for mounting said prism, said detector mounting legs having their ends secured to said prism mounting plate, said light source mounting structure being secured to said mounting plate and said prism mounting plate including an aperture for passing light from said light source to said prism, and back from said prism to said detector.

Claim 3

The refractometer of claim 1 wherein said detector mounting structure is secured to walls that receive heat conducted from liquid being measured, said mounting structure is of heat-conductive material, and cooling structure defining a cooling flow path is arranged to contact said detector mounting structure between said carrier member and the point of attachment of said mounting structure to said walls, thereby to protect the detector from heat.

Claim 4

The refractometer of claim 4 wherein said carrier member is of heat-conductive material and is in heat-conductive contact with said cooling structure whereby heat radiating from the region of said liquid to said carrier member is conducted away from said detector.

Claim 5

The refractometer of claim 5 wherein said heat-conducting contact is at least partially through said linear guide means and said adjusting means.

Claim 6

The refractometer of claim 2 including cooling structure comprising metallic conduits in contact with an intermediate portion of said mounting structure between said carrier member and said liquid for circulating a cooling substance continually along said mounting structure, whereby heat conducted through said legs from said liquid is substantially removed from said mounting structure prior to reaching said carrier member.

Claim 7

The refractometer of claim 2 adapted for in-line operation wherein said detector legs are secured to a prism mounting plate and said mounting plate is secured to means forming an opening in a liquid flow directing body to expose the interface surface of the prism to liquid therein, said body defines upstream and downstream conduits constructed to provide a liquid path to and from the prism, said upstream conduit is disposed to deliver a stream of liquid along said plate and at an acute angle to said prism surface, said downstream conduit is disposed to receive liquid at an oppositely directed acute angle to said prism surface, and said prism surface and mounting plate are positioned to deflect and redirect liquid flow from said upstream to said downstream conduits with the liquid flow path extending across said prism surface.

Claim 8

The refractometer of claim 1 for measuring the refractive index of a liquid sample, wherein said refractometer also includes a sample holder for maintaining said liquid sample upon said prism surface, and a closure member for forming with said holder and said prism surface a stray light-impermeable chamber for said liquid sample.

Claim 9

The refractometer of claim 9 wherein said sample holder defines an interior frustoconical bore, and said prism surface is located at the truncated apex of said conical bore.

Claim 10

The refractometer of claim 10 wherein said closure means includes a resilient cap having an outer surface shaped to press-fit into said conical bore to form a lighttight seal above said liquid.

Claim 11

The refractometer of claim 10 wherein said resilient cap has a lower conical portion having a surface parallel to said prism surface and sized to be spaced slightly therefrom and an outer wall matching the adjacent sample holder wall, and an upper cylindrical portion forming a channel for excess liquid sample squeezed out from between said parallel surfaces and said matching conical surfaces.

Claim 12

The refractometer of claim 9 including mounting structure for said closure member comprising a retractable arm and biasing means for biasing said closure means against said holder to form said stray light-impermeable chamber.

Claim 13

The refractometer of claim 13 wherein said arm is pivotably mounted on a bridge member remote from said sample holder, and arcuately retractable from said sample holder, and said biasing means are constructed to be inoperative when said arm is arcuately retracted from said sample holder.

Claim 14

In a critical angle refractometer for continually measuring the refractive index of a liquid stream flowing through a line by determining the critical angle at which a light beam directed through a prism at a surface of said prism exposed to and forming an interface with said stream is reflected back through said prism from said interface, the improvement comprising a one-piece stream-directing member for directing said stream along said prism surface comprising, a liquid inlet, a liquid outlet coaxial with said inlet, said inlet and said outlet arranged for connection in said line so that the entire liquid stream flowing through said line also flows through said stream-directing member, an upstream conduit arranged to deliver said liquid stream from said liquid inlet in to said prism surface at an acute angle to said prism surface, a downstream conduit arranged to deliver said liquid stream from said prism surface to said outlet at an oppositely directed acute angle to said prism surface, a smooth, continuous surface joining said conduits and shaped to define a weirlike diverter member between said conduits, the liquid flow path between said conduits being across said diverter member, and means mounting said prism with said exposed prism surface located opposite to and facing said diverter member whereby the liquid stream flowing across said member between said conduits flows across said prism surface and is deflected and redirected by said prism surface.

Claim 15

The refractometer of claim 15 wherein said stream-directing member is a standard valve body.

Claim 16

The refractometer of claim 15 wherein said prism mounting means is constructed to define an opening of frustoconical cross section having said prism surface secured at its truncated apex opposite said weirlike diverter member, said stream-directing member and said opening being structured to provide a relatively smooth liquid flow path.

Claim 17

The refractometer of claim 15 wherein said upstream and downstream conduits of said stream-directing member are formed integrally each of said conduits includes a portion of circular cross section adjacent the respective liquid inlet and outlet openings, the conduits being sloped outwardly at opposed angles from their respective openings, the outer walls of said conduits terminating in a common portion of circular cross section perpendicular to and of greater diameter than either of said inlet or outlet openings, and the inner walls of said conduits joined together to form said weirlike diverter member.

Claim 18

The refractometer of claim 17 wherein said prism mounting means and said stream-directing member being secured together, in a liquidtight seal, by flanges having parallel sealing surfaces extending radially outwardly from the base of said conical opening and from the adjoining portion of said stream-directing member.

Claim 19

In a critical angle refractometer for continually measuring the refractive index of a liquid stream flowing through a line by determining the critical angle at which a light beam directed through a prism at a surface of said prism exposed to and forming an interface with said stream is reflected back through said prism from said interface, the improvement comprising a one-piece stream-directing member for directing said stream along said prism surface comprising, a liquid inlet and a liquid outlet, said inlet and said outlet arranged for connection in said line so that the entire liquid stream flowing through said line also flows through said stream-directing member, an upstream conduit arranged to deliver said liquid stream from said liquid inlet in to said prism surface at an acute angle to said prism surface, a downstream conduit arranged to deliver said liquid stream from said prism surface to said outlet at an oppositely directed acute angle to said prism surface, each of said conduits including a portion of circular cross section adjacent the respective liquid inlet and outlet openings, the conduits being sloped outwardly at opposed angles from their respective openings, the outer walls of said conduits terminating in a common portion of circular cross section perpendicular to and of greater diameter than either of said inlet or outlet openings and the inner walls of said conduits joined together to form a smooth, continuous surface, said surface being shaped to define a weirlike diverter member between said conduits, the liquid flow path between said conduits being across said diverter member, and means mounting said prism with said exposed prism surface located opposite to and facing said diverter member whereby the liquid stream flowing across said member between said conduits flows across said prism surface and is deflected and redirecteD by said prism surface.