The TiePie engineering measuring instruments are not designed to handle the voltages that are normally present on the power outlet. Therefore, the use of a Differential Probe, like the SI-9002 is mandatory. If you do not use the Differential Probe, it's likely that your measuring equipment is damaged permanently!

When you want to start measuring, make sure that the SI-9002 probe is powered by either the supplied batteries or an external power adaptor. Do not connect any cables yet and check if the power led is lit when you switch the power button to '1'. Turn the Differential Probe off again after you've verified that it's properly powered.

Next, verify that the attenuation ratio is set to 1/200. If this ratio is set lower, it might also damage your equipment! Once you're certain that the Differential Probe is set up correct, connect the BNC connector to any channel of the TiePie engineering measuring instrument you own. The final step is to connect the probe to the power outlet. Maybe you will need a convertor of some kind, but that is region dependant.

Start up the software once the probe has been properly set up and pick the measurement you want to perform. For example, if you would like to show the signal in the oscilloscope, start up the oscilloscope and power up the Differential Probe. Because the Differential Probe has an attenuation ratio of 1/200, this ratio should be corrected in the software to get the actual voltages that are present on the power outlet. Therefore, right click on the vertical axis of the channel you've selected to connect the SI-9002 to and select the option Units gain .... In the following window, enter the correction value for this Probe, which is 200 in this case. Hit 'enter' or click Continue and your voltage axis should now list the correct voltage.

Note that the oscilloscope doesn't display 230V (for Europe) or 110V (for North America) since the oscilloscope only shows the peak-peak voltage between the two peaks of the sine wave, instead of the RMS value in which the voltage on the power outlet is listed.

As explained before, it's possible to perform another measurement while the oscilloscope is being used. So, we will also list the voltage, the frequency and the duty-cycle that is present by means of the voltmeter.

Start the voltmeter up in the instrument taskbar and verify that the channel you've selected to show the outlet voltage is displayed in the voltmeter. Right-click on the either of the displays in the voltmeter and select the option Units per measurement unit. Once again, we have to correct the attenuation ratio by entering 200. If you've selected True RMS in the Measurement menu of the display by right clicking in the display, it should now show the RMS voltage of your power outlet.

If you're trying to measure other voltages too in another display of the voltmeter, make sure that you correct the attenuation ratio of the Differential Probe in those displays as well. Obviously, there is no need to correct for non-voltage related measurements, like the duty cycle or the frequency.

As can be seen above, in the image of the oscilloscope, the sine wave of your power outlet is not exactly your typical sine. A lot of distortion occcurs, resulting in a somewhat square top end of the wave. This is, offcourse, an interesting phenomenon that calls for further investigation. The spectrum analyzer is the ideal instrument for all frequency related information, therefore we will use it to get a quick insight in the distortion figures on the power outlet.

Locate the spectrum analyzer on the instrument taskbar and run it. Right-click on the vertical axis and set up the axis type correctly by choosing Logarithmic from the Axis type menu. Use your mouse to adjust the offset of the vertical axis by dragging the center of the vertical axis upwards. Moreover, don't forget to correct the frequency range by pressing F3 and F4 and set it to a value in the range of 2 KHz. If needed, a different window function can be selected as well by pressing the Window button in the taskbar. This might help correct some errors in the FFT function that may occur. In the image above, a Welch window function has been used.

The spectrum of the power outlet that was used to create the images on this page shows that the 3rd harmonic is pretty much non-existent, but the 5th harmonic (at 250 Hz) is a lot bigger again. As we further progress in the spectrum, the amplitudes of the peaks are further decreasing, but still present. This explains the 'flat' top ends of the sine wave from the power outlet.

The spectrum analyzer of the TiePie engineering Windows software also has a function to calculate the THD of the measured signal directly, by pressing the THD button in the taskbar. For example, the THD of the power outlet at the TiePie engineering main office is listed at -34.5 dB.