Abstract: A salt bridge for a flow cell which includes a porous bridge element between fluid flow in the flow cell and in an internal reference fluid flow. The bridge element is surrounded by a body with a bore into which different tubes are located about the porous element. A cylindrical anchoring tube adjacent one end of the body is screw threaded into an aperture in the wall of the flow cell so that self-alignment of the salt bridge in the flow cell is effected. The salt bridge provides a conductivity path between the two flow paths without introducing another potential.

Abstract: An automatic chemistry analyzer includes a flow cell mounted so that flow through the cell and tubing connected to the cell is visible from the front of the housing. The electrolytes to the cell are removably plugged into the cell from their rear. The probe aspirating sample fluid into an injection cell is simultaneously washed by diluent and the diluent mixes with the fluid sample. Waste fluid from the flow cell is fed to a basin which then feeds under gravity to a waste drain. A ratio pump is formed by selected syringes which are band driven to deliver accurately prerequisite volumes of reagents to the flow cell. The solution ground to the system is on the inlet line for sample adjacent the entrance to the flow cell of fluid thereby minimizing electronic noise. Only two motive means are necessary, one to effect horizontal and rotational movement of the sample tray, and a second to effect vertical motion of a crane mounted probe operative between sample cups and an injection cell.

Abstract: An automatic chemistry analyzer includes a flow cell mounted so that flow through the cell and tubing connected to the cell is visible from the front of the housing. The electrolytes to the cell are removably plugged into the cell from their rear. The probe aspirating sample fluid into an injection cell is simultaneously washed by diluent and the diluent mixes with the fluid sample. Waste fluid from the flow cell is fed to a basin which then feeds under gravity to a waste drain. A ratio pump is formed by selected syringes which are band driven to deliver accurately prerequisite volumes of reagents to the flow cell. The solution ground to the system is on the inlet line for sample adjacent the entrance to the flow cell of fluid thereby minimizing electronic noise. Only two motive means are necessary, one to effect horizontal and rotational movement of the sample tray, and a second to effect vertical motion of a crane mounted probe operative between sample cups and an injection cell.

Abstract: An automatic chemistry analyzer comprises discrete sample cups about the circumference of a carousel. A motor selectively moves the sample cups towards and away from a target location where a probe is located for reciprocal vertical motion. The motion is timed for reaction with a sample cup so that when the sample cup is in position at the target location, the probe removes fluid from the sample cup. When the sample cup is moved from position, the probe aspirates fluid into an injection cell below the sample cup. A vertical motion only is imparted to the probe, while the sample cups move under the action of a single motor horizontally and laterally to define a rotational movement.

Abstract: An automatic chemistry analyzer includes sample cups circumferentially located on a sample wheel. Means moves the sample cups rotationally under cycloidal action to and away from a target location where a probe operates vertically in relation to the sample cups and an injection cell. The motion is effected by a cam operating with a cam follower formed by lobes circumferentially located about a drive wheel which houses the sample wheel or carousel.

Abstract: The sample injection cell comprises a body and a bore through the body for receiving a probe to pass fluid sample into the bore. A transverse passageway into the body permits a diluent to enter the bore and be mixed with a sample in a predetermined ratio and be dispensed directly into the flow cell. The diluent simultaneously washes the probe when the probe is located in the bore. A waste basin forms part of an integral unit and is adjacent the bore so that fluid from a flow cell can enter the waste basin and then exit under gravity to a waste drain.

Abstract: An automatic chemistry analyzer includes a flow cell mounted so that flow through the cell and tubing connected to the cell is visible from the front of the housing. The electrolytes to the cell are removably plugged into the cell from their rear. The probe aspirating sample flud into an injection cell is simultaneously washed by diluent and the diluent mixes with the fluid sample. Waste fluid from the flow cell is fed to a basin which then feeds under gravity to a waste drain. A ratio pump is formed by selected syringes which are band driven to deliver accurately prerequisite volumes of reagents to the flow cell. The solution ground to the system is on the inlet line for sample adjacent the entrance to the flow cell of fluid thereby minimizing electronic noise. Only two motive means are necessary, one to effect horizontal and rotational movement of the sample tray, and a second to effect vertical motion of a crane mounted probe operative between sample cups and an injection cell.

Abstract: A salt bridge for a flow cell which includes a porous bridge element between fluid flow in the flow cell and in an internal reference fluid flow. The bridge element is surrounded by a body with a bore into which different tubes are located about the porous element. A cylindrical anchoring tube adjacent one end of the body is screw threaded into an aperture in the wall of the flow cell so that self-alignment of the salt bridge in the flow cell is effected. The salt bridge provides a conductivity path between the two flow paths without introducing another potential.

Abstract: A sample handling system including a sample injection cell having an open chamber in turn comprising an upper portion for washing a sample handling probe and a lower portion adapted to reeive the probe for injection of a sample and fluid mixture into a flow analysis device. The cell enables the probe to be withdrawn from the cell and moved to other analysis modules for injection of sample therein. The cell includes a seal between the upper portion and lower portion of the chamber and the probe includes a mating seal near the tip of the probe. A plurality of conduits are formed into the cell for flowing sample and a fluid such as diluent through the cell to a flow analysis device and for filling the cell for washing the probe tip.

Abstract: A method and apparatus for determining an insufficient liquid volume. The invention includes an electromagnetic sensing device in a conduit into which the sample liquid is mixed. The electromagnetic sensing device detects the presence of air in the conduit which indicates that an insufficient liquid volume has been aspirated.