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https://github.com/arup-group/pqm-hellebores/
Follow the installation and setup instructions in the README.md file.
Connect input and output IEC leads and apply power. The switch on the box controls output power to the load. After the Raspberry Pi has booted, a launcher should appear on the screen from where you can start the application.
The machine will start in a waveform capture and display mode. You can display up to four different time-correlated waveforms: voltage, current, power and earth leakage current. The selection of waveforms and the vertical and horizontal scales are available on the 'Horizontal' and 'Vertical' controls.
If you want to freeze the image on the display, use the 'Start/Stop' button.
To change the waveform alignment/trigger point, use the 'Trigger' button. You can also disable the trigger entirely by selecting 'Free run'.
Use the 'mode' button to switch to multimeter mode. The software will analyse a 2 second buffer of sample readings and update the display every 1 second.
Measurements include: RMS voltage, RMS current and RMS earth leakage current, instantaneous power, VAR and VA, power factor, crest factor, total harmonic distortion (V and I), cumulative Wh, VARh and VAh. The multimeter also tracks maximum and minimum extrema of several measurements.
The hardware has two current ranges, 'low' and 'full' range. A warning indication will show on the display if you are in low range. The low range will provide enhanced resolution at very low levels of load, which can be useful for quiescent/standby power measurements. However if instantaneous current exceeds 0.2A then the ADC channel and protection circuit is liable to saturate. The 'full' range should therefore be used for the majority of measurements.
Multimeter calculations including cumulative measurements continue regardless of the display mode, to allow long term measurements to be made while using other functions. Cumulative measurements and max/min extrema can be cleared using the 'Reset' button.
Individual harmonic voltages are displayed from h0 (DC) through to h50. The software will analyse a 1 second buffer of sample readings and update the display every 1 second.
Harmonic magnitudes are displayed as a dimensionless percentage of the RMS voltage of the system. In the internal FFT analysis, harmonic frequency bins are approximately 1 Hz wide. The appropriate bin for each harmonic frequency is determined dynamically based on the measured fundamental frequency of the system.
Individual harmonic currents are displayed from h0 (DC) through to h50.
As per harmonic voltage display, the harmonic current magnitudes are displayed as a dimensionless percentage of the RMS current of the load, and the FFT bin selection is automatic.