FRITSCH PULVERISETTE 6 classic line - Manual (Page 5)

GTM-System page 2
1.3 Brief Description of the Instrument
1.3.1 Applications
The Measuring System GTM grasps simultaneously gas pressure and
temperature in the grinding-bowl during the grinding in Planetary Mills.
This allows a variety of statements to the description of the running
comminuting, mixing, activating, amorphysing or phase-conversion proc-
esses.
• The measured gas-pressure gives information based on the
temperature-alterations in the grinding-bowl. It describes the
interaction of the implied gas with the surfaces created with
the grinding (adsorption and desorption of gases) with consid-
eration of the entire powder-volume.
• The measuring of the basic temperature of the system with a
temperature-sensor enables one to consider the temperature-
influence on the gas-pressure in a limited scope.
Slow alterations of raw material states are a fundamental application
during the grinding process, like the amorphysing of metals. Such tests
can last for many hours. A fast data-reception is not necessary.
A second important application of high energy grinding is the attainment
of phase-development or alterations due to the mechanical alloying.
With this, extremely fast reactions can occur, which are measured and
recorded with a high measuring rate by the GTM-System.
1.3.2 Method of Operation
A micro-electronic silicon-membrane-pressure-sensor and a tempera-
ture-sensor are being used as detectors, which are installed in a modi-
fied grinding-bowl (transmitter module). The measurements from the
sensors are digitally transmitted to an unmoving receiver, which is exte-
rior to the mill.
In the receiver, the data-telegrams are checked for completeness and
correctness and are transferred over to a serial RS 232 - interface on a
pc.
The computer-program calculates the measurements from the received
data and displays it graphically in relation to the time. The measure-
ments can be saved and loaded into a spreadsheet and there proc-
essed.
The power supply is made up of rechargeable accumulators in the
transmitter module.
The data of two grinding-bowls can be analyzed simultaneously if two
transmitter modules are connected.