Institut De Recherches De La Siderurgie Francaise

Institut De Recherches Siderurgie Francaise

Bernard Boury

Gerard Willay

Andre Wittmann

Jean Philippe

Georges Heitz

A device for determining the moisture content of a material which includes a micro wave heating unit (1) for heating a sample of the material which is under investigation and a weighing device (3) for weighing the sample during heating and providing signals representing a series of measurements of the weight of the sample at specific times. The weighing device is connected to a processing unit (4) which is a microprocessor and which includes a computer (9) which produces signals representing the loss of weight of the sample in the course of heating and which computes the parameters of a asymptotic function and which represents the loss of weight of the sample in the course of time. There is also a calculator (11) for determining the differences between two asymptotic values, and a comparator (12) for comparing the differences with a reference value representing the acceptable uncertainty in regard to the moisture content of the material. There is also a restoring device for restoring the asymptotic values when the differences reach values which are equal to or less than the reference value.

Apparatus for the rapid determination of the moisture content of a

A sample of the steel to be analyzed is subjected to spark discharging, the optical emission of the sparks is directed onto a diffraction grating in order to separate the light emission corresponding to the element to be metered and a capacitor is charged by a current respective of the intensity of this radiation; after every elementary discharge of the integration circuit, the charge of the capacity is converted into the form of a digital data representative of the intensity of the line selected; during a spark discharging cycle, the number of intensities is determined of which the value is included in each one of a plurality of contiguous channels, in order to set up an intensity frequency diagram as a function of the intensity; the curve representing the diagram is smoothed and the content of dissolved element is determined as a linear function of the value of light intensity corresponding to the peak of the gaussian part of the smoothed curve; and the content of precipitated element is determined by summing products n.sub.i, C.sub.i for all the channels located beyond the gaussian part, on the high intensity side, where n.sub.i and C.sub.i are the number of pulses in channel i, and the middle intensity of channel i, respectively.

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Metz, France

Bernard Boury