Ash-Monitor

A program that uses only advanced math does not help the user: it must be applicable.

The  ash analyzer must be able to be calibrated without an extended mathematical background.

For  this purpose, a table is saved in the evaluation unit, in which laboratory values ​​can be stored and used as a comparison.

An  automatic routine for determining the calibration curve determines the coefficients and immediately shows how good the adjustment was.

It  is not only important to simply display the measurement results. The table already mentioned can be used as a data store. All measured values ​​are displayed over a period of 1 hour, 1 shift and 1 day back for 30 days.

In  the service menu, the software can change the assignment of the wiring terminals so that a relay or an analog output can be switched from one terminal to another.

Therefore,  the evaluation unit is not only an indicator for ash, but also fits into the process and can help with the control.

Some  influences are responsible for possible errors and good or bad accuracy.

Extracted hard coal or brown coal can usually be determined with an accuracy of better than ± 0.5% standard error for about 10% ash.

For  ash contents below 10%, even better results are achieved, while with higher ash contents - however not because of the principle but because of the higher error of the laboratories - the error is higher.

The  system must be calibrated with a laboratory error of 0.3% and is therefore of limited accuracy.

The  most important possible error is caused by the coal itself: while the measuring principle is based on the distinction between two components, in reality there are about ten, i.e. any change in the composition of the ash causes a minor error.

Since  the two main components have almost the same absorption coefficient, this ratio does not lead to a false indication, which is why attention must be paid to such changes as the iron content.

The  theoretical error can be very large, but is not very important in practice. Nevertheless, it must be observed, where another mistake can be caused by the moisture content.

Only  if the ash content is approx. 5 - 10% will no error be caused since water is measured as coal, but higher content can lead to an error, which, fortunately, can be compensated for with an RGI microwave moisture meter.