摘要:
A solenoid serves for generating a magnetic field at the location of a sample which is to be atomized in an atomic absorption spectrometer. A shift of the absorption lines of the atoms in a sample relatively to the emission lines in a measuring light beam (18) passed through the atomized sample is effected by the magnetic field due to the Zeeman effect. The solenoid (44) comprises a pair of pole pieces (46, 48) between which an air gap is formed. An atomizing device atomizes the sample within this air gap. Field coils generate a magnetic flux through the pole pieces (46, 48), the air gap and a magnetic return path (76). The field coils (60, 62) are arranged on pole pieces (46, 48) close to the air gap. The windings of the field coils (60, 62) are formed by tubes (216) which are designed to permit passage of a cooling liquid therethrough.
摘要:
A burner assembly for an atomic absorption spectrometer having carrier (20) fixed to the burner head (14) and mounting a flame sensor (96) and an ignition device (16) so as to permit a single alignment of the flame sensor (18) and the ignition device (16) relative to the burner head (14) and subsequent movement or adjustment of the burner relative to the housing without changing the mutual positions of the ignition device (16) and the flame sensor (18) and while the flame is burning.
摘要:
An Atomic Absorption Spectrometer in which background absorption is compensated by means of a magnetic field causing a periodic line shift due to the Zeeman Effect, including a line emitting light source, an atomizing device, an optical system, by means of which the measuring light beam can be passed through an atom cloud of the atomizing device, an electromagnet, a converter circuit for converting the mains a.c. voltage into d.c. voltage applied to a capacitor, the winding of the electromagnet being located in the diagonal of a bridge circuit which is supplied with the d.c. voltage of the circuit and comprises a diode in diametrically opposite branches and a first and second controlled switch in the other two branches, the first one of the controlled switches being periodically maintained conductive by controls at the frequency of energizing and de-energizing the electromagnet, during an active time period encompassing the build-up and maintenance of the magnetic field, the first controlled switch being non-conductive during the remaining time, the second one of the controlled switches being controlled by means of a two-step current controller for regulating a predetermined current flowing through the winding of the electromagnet during the active time period of the first controlled switch, the second controlled switch likewise being non-conductive during the remaining time so that there results an essentially trapezoidal current waveform, and the winding of the electromagnet being connected in series with the diodes to the capacitor of the converter circuit in the non-conductive state of both of the controlled switches.
摘要:
An atomic absorption spectrometer with electrothermal atomization of the sample and background compensation by use of Zeeman effect comprises a furnace (130) for the electrothermal atomization of the sample which furnace is heated transverse to the direction of propagation of the measuring light beam (18) of the atomic absorption spectrometer and a switchable solenoid (44) for generating a magnetic field at the location of the sample which magnetic field extends parallel to the direction of propagation of the measuring light beam (18) such that the longitudinal Zeeman effect is obtained with switching on the solenoid (44). The solenoid (44) has pole pieces (46,48) with aligned apertures (50,52) for the passage of the measuring light beam (18). A contact carrier (96) is arranged on the pole pieces (48,50) in which contact carrier contacts (128,176) are supported in order to hold the transversely heated furnace (130), the axes of said contacts being perpendicular to the axis of the measuring light beam (18). Field coils (60,62) are arranged directly on the pole pieces (46,48). The contact carrier (96) forms an integral element with the coil holder (56,58).
摘要:
In an atomic absorption spectrometer with an atomizing device (190) and a line emitting light source (16), an optical system (22,28 . . . ) for generating a measuring light beam (18), and a photo-electrical detector (38), which are arranged in a housing (10) which forms a sample cavity (12) accessible from the outside and which is passed through by a measuring light beam (18) and into which different atomizing devices can be optionally inserted, the atomizing device (190) with the specific components (104,124,126) is assembled to form an insert unit (100) in which the atomizing device (190) in the form of a graphite furnace has a well-defined position relatively to the insert unit (100) and which in turn can be inserted into the sample cavity (12) in a well-defined position to provide an entirely functioning atomic absorption spectrometer.