Abstract: A spectrometer using Zeeman background correction is disclosed which has a sample producer (100) for producing a cloud of atoms, an electromagnetic radiation source (102) for irradiating the atom cloud, a detector (104) for detecting the radiation after it passes through the atom cloud and an electromagnet (14) for applying a magnetic field to the atom cloud. A power supply and switching unit (106) for powering the electromagnet and switching the electromagnet on and off to create a Zeeman effect are provided. The switching unit has transistors (16-22, 40, 42, 50, 52) controlled by a control circuit (25), and the power supply includes a rectifier (10) and one or more capacitors (12, 12a, 12b). The switching time is typically on the order of 1-1.5 ms or less and the high voltage which is applied is on the order of 400-800 V.

Abstract: A method relating to deposition of a liquid sample mixture in the tubular furnace of a spectrophotometer. The method involves drawing a quantity of each ingredient of the sample mixture into a conduit in a predetermined sequence and also drawing a slug of air into the conduit immediately following the uptake of each ingredient. In the result, a segmented fluid stream is created in which a slug of air separates each two adjacent ingredient segments. The conduit is initially filled with a rinsing fluid and the segmented fluid stream displaces some of that rinsing fluid from the conduit. A slug of air separates the rinsing fluid from the segmented stream. The segmented stream is then discharged in a single operation into the furnace of the spectrophotometer so that mixing of the ingredients occurs at or adjacent the furnace surface.

Abstract: Heating apparatus particularly for flameless atomization in spectrophotometers includes a variable electrical power source and a resistive heating element. A desired final temperature and the rate of change of the element temperature (ramp rate) is input to a control circuit. A storage means is provided for storing data relating the heating element temperature to the energy input (voltage) to the heating element required to maintain the heating element at a constant temperature. Processing means calculates from the various data the voltage required to be supplied to the element by the power source to change the temperature thereof at the selected ramp rate until it reaches the final temperature. In spectrophotometers the apparatus accurately controls the carbon rod temperature through drying, ashing and atomizing stages.

Abstract: A method relating to deposition of a liquid sample mixture in the tubular furnace of a spectrophotometer. The method involves drawing a quantity of each ingredient of the sample mixture into a conduit in a predetermined sequence and also drawing a slug of air into the conduit immediately following the uptake of each ingredient. In the result, a segmented fluid stream is created in which a slug of air separates each two adjacent ingredient segments. The conduit is initially filled with a rinsing fluid and the segmented fluid stream displaces some of that rinsing fluid from the conduit. A slug of air separates the rinsing fluid from the segmented stream. The segmented stream is then discharged in a single operation into the furnace of the spectrophotometer so that mixing of the ingredients occurs at or adjacent the furnace surface.