Sartorius

Volker Handwerk

Gunther Maaz

Erich Knothe

Christian Oldendorf

Franz-Josef Melcher

Klaus Nottbohm

A drying balance is disclosed with a means (11) for supplying energy for the drying of material to be weighed located on the balance scale (6,16) and with a digital evaluating unit (23,24,25) for calculating the moisture content from the measured weight loss of the specimen and for determining the end point of the drying in which balance the digital evaluating unit (23,24,25) calculates the inflection point from the chronological course of the weight loss and derives the criterion for determining the final point therefrom. The criterion for the final point consists in that the slope of the drying curve drops below a certain value which is derived from the coordinates or the slope of the drying curve at the inflection point.

Drying balance with evaluation circuit for determining the end of the

A drying balance with a radiation source (11) for heating and drying a substance distributed on a balance scale (5), with a temperature sensor (8) for monitoring and controlling the output of the radiation source (11) and with electronic evaluating circuitry (33) for evaluating the measured values of the balance and for controlling the drying balance that a temperature gauging disk (14) with another temperature sensor built in be used in order to determine in a temperature gauging cycle the deviation of the output signal of the temperature sensor (8) from the output signal of the other temperature sensor built into the temperature gauging disk (14) and to calculate a correction factor from them and to store this correction factor. Then, the output signal of the temperature sensor (8) is multiplied by this correction factor during dryings in order to obtain the true temperature of the substance. Different coefficients of absorption of different substances can be mimiced by surfaces on the temperature gauging disk which exhibit different sizes and a high absorption capacity or a low absorption capacity.

Drying balance with temperature control

In a drying balance with scale on top and with a radiation source for heating and drying material to be weighed located on the balance scale, the radiation source (11) is permanently located behind the balance scale (5) and a bent cover (7) which functions as a radiation deflector is movably located over the balance scale (5). This makes the construction lower and a moving of the radiation source (11) with its electric connections is avoided when the balance scale (5) is loaded. Moreover, differently constructed inner surfaces (7') of the cover (17) permit the drying balance to easily adapt to different radiation sources (11) and to different drying tasks.

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Bovenden, Germany

Volker Handwerk