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The pump head liner of a small-size precision reciprocating metering pump, which has its application particularly in High Performance Liquid Chromatography (HPLC), is made of transparent material, preferably of synthetic sapphire or monocrystalline zirconium oxide. A pump head casing is designed suc

The pump head liner of a small-size precision reciprocating metering pump, which has its application particularly in High Performance Liquid Chromatography (HPLC), is made of transparent material, preferably of synthetic sapphire or monocrystalline zirconium oxide. A pump head casing is designed such that a pump head liner is visually accessible. Cartridge-type check valve units abut onto the pump head liner on the one side, and onto a connecting adapter piece featuring an elbow liquid duct on the other. Pre-loading pressure for liquid sealing is exerted onto the connecting adapter piece by means of a compression screw which is secured in a clamp bracket or L-shaped angled clamping piece. The cartridge-type check valve units can be composed of transparent components and thereby are visually accessible. The opening and closing of a ball in a check valve unit can be monitored by an optical sensing system in order to obtain a feed-back signal for governing a control circuitry, having the purpose of compensating the influence of the specific compressibility of the liquid being pumped, upon the pumping efficiency of the displacement system under conditions of high and highest working pressures. An alternate embodiment has the pump head casing and mounting flange of one-piece construction. The pump head casing has a pair of spaced yoke arms to receive a pump head liner and vertical slots for mounting of check valve modules.

대표청구항 ▼

A precision reciprocating metering pump, especially as applied in High Performance Liquid Chromatography (HPLC) techniques comprising a pump head casing, a pump head liner mounted in said pump head casing and containing a displacement chamber as well as inlet and outlet ports therein, and a plunger

A precision reciprocating metering pump, especially as applied in High Performance Liquid Chromatography (HPLC) techniques comprising a pump head casing, a pump head liner mounted in said pump head casing and containing a displacement chamber as well as inlet and outlet ports therein, and a plunger piston of clearance fit within said displacement chamber, said pump head liner and plunger piston being constructed of chemically inert material, the improvement wherein the pump head liner is formed of transparent synthetic sapphire or transparent monocrystalline zirconium oxide and the pump head casing is fitted with at least one viewing opening through which said pump head liner may be viewed from the exterior of the pump head casing.