Automatic analysis of the dissolved gases in oil-filled transformers, The analysis is done in 2 steps which guarantee a very high selectivity and sensitivity.in the determination of dissolved gases:

1. Gas separation by means of fully vacuum degassing ( accord. to DIN EN 60567,DIN IEC 599 and IEEE C57.104-1991) and display of results

2. Option: Following the determination of the total gas content a gas chromatographic analysis can be made.

Both steps are synchronized via a micro-processor control thus a fast and reliable measurement procedure is guaranteed.

A newly invented vacuum degassing method , de-gasses the oil sample periodically. After extraction through a 4 step vacuum pump the gases are dosed into vacuum chamber and separated. The gases are evacuated from the vacuum chamber with a vacuum pump; therefore a very high accuracy can be achieved.

In and outlet of the oil sample as well as the switching valve are micro-processor controlled, a feedback of the oil into the transformer is possible. A linear pressure sensor measures the total gas content online which is a very important quality parameter for the characterization of the transformer load.

The injection of the gas sample into the gas chromatograph is via a fixed mount and heated transfer pipe. An additional port for withdrawal of gas samples is installed.

The system is controlled by a micro-processor; a serial interface (RS 232) allows for transferring the data to a remote computer. The intervals of the analysis cycle can be freely defined by the operator (number of analysis/day or hour).

The system has 8 additional analog inputs (0 -1 V) for the measurement of other transformer parameters (Oil temperature, winding temperature, ambient conditions etc.) The connection of these external sensors is through relay contacts (N/C or N/O, to be specified by the customer).

All results of the total gas content are displayed in Vol% and are stored in a databank.

The results are displayed on the monitor, in a spreadsheet and in a printed report. All these data can also be transferred and displayed on a remote computer. All data is continuously stored in a measurement file.

The results are stored together with all measurement parameters in a log.file. The history of the stored data starts with the day of commissioning and covers several years.