*Question E8A05:
What is the benefit of making voltage measurements with a true-RMS calculating meter?*  

*Correct Answer is  D: RMS is measured for both sinusoidal and non-sinusoidal signals*  

### AI Response: (may contain errors)  

To understand the benefits of using a true-RMS (Root Mean Square) calculating meter, let's break down the correct answer and the other choices.

### Correct Answer: 
**D: RMS is measured for both sinusoidal and non-sinusoidal signals.**

- **Explanation**: A true-RMS meter accurately measures the effective voltage of both sinusoidal and non-sinusoidal waveforms. This is important because many real-world signals are not pure sine waves (e.g., square waves, triangular waves, or complex waveforms). A true-RMS meter calculates the RMS value based on the actual shape of the waveform, providing a reliable measurement of the voltage that corresponds to the power delivered to a load.

### Why the Other Choices are Incorrect:

- **A: An inverse Fourier transform can be used**  
  - **Explanation**: This statement is not relevant to the function of a true-RMS meter. An inverse Fourier transform is a mathematical operation used in signal processing to convert frequency domain data back to the time domain, but it does not pertain to the measurement of RMS voltage.

- **B: The signal’s RMS noise factor is also calculated**  
  - **Explanation**: While a true-RMS meter can measure the RMS value of a noisy signal, it does not specifically calculate an "RMS noise factor." The term "noise factor" typically refers to a measure of degradation in signal-to-noise ratio in amplifiers, not a direct measurement made by a true-RMS meter.

- **C: The calculated RMS value can be converted directly into phasor form**  
  - **Explanation**: While RMS values can be used in phasor calculations, the conversion to phasor form typically involves complex numbers and phase angles, which is not a direct function of a true-RMS meter. The meter provides the RMS value, but additional calculations are needed to convert that value into phasor form.

### Summary:
- A true-RMS meter is essential for accurately measuring the effective voltage of both sinusoidal and non-sinusoidal signals, making it a valuable tool in various applications. 

### Useful Rule of Thumb:
- For sinusoidal signals, the RMS value can be calculated as:
$$
V_{RMS} = \frac{V_{peak}}{\sqrt{2}}
$$
- For non-sinusoidal signals, use a true-RMS meter to obtain the correct RMS value directly.