Abstract: The present invention is directed to a lamp assembly for use in atomic absorption spectrometers in which an atomic element hollow cathode lamp assembly has a lamp formed by a hollow cathode electrode and an anode electrode within a sealed envelope. A base structure is attached to the envelope, and located within the base structure is a resistor network consisting of four resistors connected to a common lead and having four plug terminals protruding from the base structure. Two further plug terminals also protruding from the base structure are connected respectively to the cathode and anode electrodes to provide a connecting structure for connecting these electrodes to a lamp power supply. The five plug terminals protruding from the base structure and connected respectively to the resistors and the common lead provide a further connecting structure of the resistor network to a measurement circuit in an atomic absorption spectrophotometer.

Abstract: An improved source lamp assembly for use in atomic absorption spectrophotometers is described having encoded structures for identifying the atomic element of the source lamp assembly, as well as to represent lamp operating current. The encoding structures are formed by way of mechanical, optical, or magnetic means. In particular, a mechanical arrangement involves a plurality of projections and recesses, either formed relative to a base structure of the lamp assembly or relative to an attached card-like structure. A card reading device is used to read this card-like structure. These alternative arrangements can be also used relative to optical encoding or magnetic encoding.

Abstract: A method of analyzing using an atomic absorption spectrophotometer including a flame atomizer is disclosed. The method comprises the steps of (a) setting the parameters of the spectrophotometer to a set of preset values dependent on the substance to be detected, (b) setting the gas flow rate to the burner to a preset value dependent on the substance to be detected, (c) aspirating an optimization standard into the flame, (d) measuring the absorbance of the optimization standard and storing the result, (e) modifying the gas flow rate in incremental steps and at each incremental step of flow rate repeating steps (c) and (d), and comparing the new absorbance value with the stored value until a maximum absorbance measurement is found, (f) using the maximum absorbance measurement value to select one of a plurality of sets of parameters for the spectrophotometer, and (g) subsequently aspirating and measuring the absorbance of a sample using the selected set of parameters.

Abstract: In automatic sampling arrangements for supplying liquid samples to analytical instruments, the samples are placed in open bottles in a circular ring in a turntable. The turntable is driven in rotation by a drive assembly under a sampling mechanism. To increase the storage capacity of the turntable, in accordance with the invention, a second ring of bottles is provided at a different radius to the first ring. The circumference of the turntable is provided with cut-outs with which the driving assembly engages. The driving assembly adopts one of two positions depending on the state of engagement with the cut-outs. The sampling mechanism is coupled to the driving assembly such that it adopts one of two positions in synchronism with the driving assembly positions with the first and second positions of the sampling mechanism lying on one or the other of the circular rings.

Abstract: In atomic absorption spectrophotometer, a reference path may be provided for radiation which excludes the flame. This radiation provides a signal from a detector which varies only with the instrumental drift produced by variations in the radiation source brightness and by variations in detector gain. The signal can be used to compensate for drift in other signals received through a sample path including the flame. In the present invention, radiation passes through the sample path continuously during measurement, and only through the reference path between sample measurements. Movable mirrors shift the radiation between the paths upon externally applied commands. Conveniently, the reference path measurement is made while the flame is stabilized during the change between samples. The reference path measurements are stored and used to correct for drift.

Abstract: In automatic sampling arrangements for supplying liquid samples to analytical instruments, it is convenient to have the samples in open bottles (21) in circular ranks (16), (17) in a turntable (1) indexed in rotation under a sampling mechanism (27). It is desirable to maintain the turntable horizontal while being inserted into a compartment (4) containing the sampling mechanism and a turntable drive assembly (24). Also, for easy operation, it is desirable that the turntable need not be registered accurately in the compartment. The arrangement is constructed so that the turntable is inserted, via an aperture (6) into the compartment in a direction perpendicular to its axis of rotation. The turntable is located by three bearing surfaces (29), (31) and (24) which engage the circumference of the turntable, the driving assembly (24) being one of the bearing surfaces and also engaging the circumference to rotate the turntable.

Abstract: A displaceable combination of a sample solution cell and a one-piece plastic stirrer is provided for spectrophotometry. The cell has an opening at one end through which the stirrer is inserted and arranged for reciprocation in the cell by engagement of a portion outside the cell. The stirrer is also arranged to sit in the cell during passage of radiation therethrough upon spectrophotographic measurement of the sample.