Measurement of AC voltage, switching overvoltage and pulse voltage. Replaces older technology, mainly digital oscilloscope, which was used for this measurement. The program provides oscilloscope setting, data reading and data evaluation.

AC voltage measurement

An AC voltage is generated which amplitude increases in time. The measuring device continuously measures the voltage and current. A pair of plug-in measuring boards are used for measurement, each measuring on only one channel. The sampling frequency is up to 12.5 kHz. The excitation voltage rises until the contacts of the measured object are closed. At that moment the voltage drops. The measuring system is equipped with the possibility to display measured voltage waveform before and partly after the drop. The operator selects a segment that contains all the information in the desired resolution. In the displayed section, the program searches for the maximum instantaneous voltage (absolute value, ie. without any difference between the positive and negative half-periods), which corresponds to the switching voltage. The selected measurement data are stored on the disc for further processing.

Calibration is performed over the entire measurement chain. The measuring system continuously measures the maximum value of the applied voltage, while the calibration measuring instrument indicates the correct RMS voltage value. After calibration at several points (ie. at several different voltages), a calibration curve (polynomial) is calculated over which all measured voltage values ​​are recalculated. Since the principle of calibrating the maximum value by the RMS value is used, all converted voltage values ​​are automatically reported in RMS values.

Measuring program is a standalone program capable of sending data from the selected file via the DDE link to the word processor. In the word processor, a module is created that receives data and displays them in the form of a graph, which can be integrated into the report.

Switching overvoltage measurement

During the measurement, an alternating voltage is generated, which is snap-fastened to the measured object. The measuring device continuously measures voltage and current. A pair of plug-in measuring boards is used for measurement, each measuring only on one channel. The sampling frequency is up to 12.5 kHz; higher frequencies are measured with an oscilloscope. The measuring system displays measured voltage waveform both before and partially after a drop. The operator selects a segment that contains all the information in the desired resolution. In the displayed section, the program searches for the maximum instantaneous voltage (absolute value, ie. without any difference between the positive and negative half-periods), which corresponds to the switching voltage. The selected measurement data are stored on the disc for further processing.

A calibration curve from the AC voltage measurement program is used when measuring plug-in measuring boards. When measuring with an oscilloscope, the conversion constant from the pulse voltage measurement program is used.

The measuring program is a separate program capable of sending data from the selected file via the DDE link to the word processor. In the word processor, a module receiving data and displaying them in the form of a graph, which can be integrated into the report.

Pulse voltage measurement

High voltage device generates a pulse; the measured voltage rises sharply (approx. 1.1 ms) and then gradually decreases (approx. 50 ms to 50% of the value). The maximum voltage value according to the standard must be within ± 3% around the set level. The task of the measuring program is to setup the oscilloscope, take the data after the measurement, determine the maximum instantaneous voltage value and compare it with the preset level. The operator specifies whether a voltage jump occurred and whether it wants to save the voltage waveform. The measurement is repeated several times and when measurement series finishes the statistics is calculated, how many measurements were within tolerance and what proportion of measurements ended by skipping. The statistics is stored in a data file, including the names of the data files in which the voltage waveforms for each measurement are stored.

Measuring program is a separate program capable of sending data from selected files (number of waveforms 1 to 8) via the DDE link to the word processor. In the word processor, a module is created to be receive and display data in the form of a graph, which can be integrated into the measurement report.

All programs are prepared in the TestPoint development environment.

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