Abstract: Doppler Flow Velocity Meter for the irradiation of a fluid with pulses of ultrasonic waves which are fed at a predetermined pulse repetition frequency, and for the reception of echo waves reflected by fluid particles and to emit corresponding echo signals; and having receiver connected to an ultrasonic transducer for the reception and processing of echo signals which correspond to at least two different echo waves, which are reflected by the particles in a fixed point of the flow path in response to a first and a second wave pulse emitted, in which the adjacent but separate frequency bands of the echo signal are each processed in a separate signal processing channel;The receiver containing a portion in each of the signal processing channels for carrying out a quadrature demodulation of the echo signals received from the ultrasonic transducer in each of the frequency bands, in which at the output of channels a couple of each of the quadrature signals can be obtained which define a complex measured value at eac

Abstract: A capillary flow cell in which a capillary (9) partially extends along the optical path of the cell and has its two end portions (12, 13) bent to achieve an essentially Z-shaped configuration. A template (1) has a central bore (2) in which the middle part (11) of the capillary (9) is positioned. A method of manufacture of this capillary flow cell including inserting a capillary in a central bore of a template, heating the capillary immediately outside the bore to soften the capillary material, and bending the two ends to achieve an essentially Z-shaped or U-shaped configuration.

Abstract: A capillary flow cell in which a capillary (9) partially extends along the optical path of the cell and has its two end portions (12,13) bent to achieve an essentially Z-shaped configuration. A template (1) has a central bore (2) in which the middle part (11) of the capillary (9) is positioned. A method of manufacture of this capillary flow cell comprises the steps ofa) inserting a capillary in a central bore of a template,b) heating the capillary immediately outside the bore to soften the capillary materialc) bending the two ends to achieve an essentially Z-shaped or U-shaped configuration.

Abstract: In a shunt wound d.c. motor for driving centrifuges, an apparatus for obtaining smooth acceleration by regulating the bottom speed range in accordance to a preset slope current and then accelerating the armature current with full excitation. Smooth braking is also achieved by applying to the field current the full excitation during deceleration and a preset slope current thereafter.

Abstract: A cathode-ray display for displaying a trace has a memory to store portions of digitized input signal. An analogue signal is created from the memory and is added to a ramp signal corresponding to the ramp signal utilized to control the field scanning of the cathode-ray display. A further high frequency signal is added to the superimprosed analogue signal and ramp signal. The resultant combined signal is supplied to voltage discrimination means which control a switch which, in turn, controls the electron gun of the cathode-ray display.

Abstract: A pipetting device comprising a probe for dipping into a reservoir, reaction vessel or the like, a metering pump connected to the probe and a shutoff valve disposed between the probe and the pump are provided. In the intake phase of the pump with the valve open, first air and then a predetermined quantity of liquid is intaken. For at least some of the delivery phase of the pump the valve is in the closed state so that a pressure builds up in the pump. At the end of the delivery phase the valve opens whereby due to the high pressure any adhering liquid particles are expelled.