## 3 Results and Discussion
### Reproducibility Using Cold White LED Strip  
Figure 9 includes graphical illustrations of the C-V signal dependency on kVp, mAs, SID, and dose for the cold white LED strip in the reproducibility examination. The C-V signal had a high linear dependency on the peak kilovoltage, all the data points were on the regression line. Therefore, there was a 99.76% linearity correspondence between the signal and the tube voltage. A signal increase of 0.0034 mV was observed per unit increase in the kVp.  
\begin{table}
\begin{tabular}{l c c c c c} \hline \hline  & \multicolumn{5}{c}{**LED Strip Color-Based Ranking**} \\ \hline
**Investigated Parameter** & **Cold White** & **Warm White** & **Red** & **Green** & **Blue** \\ \hline
1. C–V response to kVp & 2 & 1 & 3 & 5 & 4 \\
2. C–V response to mAs & 3 & 5 & 2 & 1 & 4 \\
3. C–V response to SID & 1 & 3 & 2 & 4 & 5 \\
4. C–V response to Dose & 2 & 5 & 1 & 3 & 4 \\
5. Consistency & 1 & 5 & 3 & 2 & 4 \\
6. Degradation & 1 & 3 & 5 & 2 & 4 \\ Cumulative Rank & 10 & 22 & 16 & 17 & 25 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Ranking of LED strips based on C–V response.  
Figure 9: _Cont._  
Similarly, the cold white C-V strip signal response to the current-time product (mAs) variation was remarkably linear: The R-squared values were 0.9713 and 0.9928 for SIDs of 60 and 30 cm respectively. Further, the linear fit for the C-V signal obtained at 30 cm SID had a higher increase in magnitude per unit increase in mAs--in comparison to the C-V signal obtained at 60 cm SID. The C-V signal as a function of SID was in the form of an exponential decay with a determinant coefficient of 0.9975. The C-V signal, in other words, decreased as a reverse square of the SID. The strip's C-V signal was also appreciably linearly dose-dependent with R-squared values of 0.9715 at 60 cm SID and 0.9879 at 30 cm SID. LED strip sensitivity to dose was highly independent of SID variation, i.e., the sensitivities at 60 cm SID (0.0126 mV/mGy), and 30 cm SID (0.0107 mV/mGy) had a 15 % disparity. In other words, LED sensitivity was 85 % similar at the 60 cm and 30 cm SIDs. Additionally, the strip's signal was consistent; consecutively measured signals 1, 2, and 3 were equivalent at 50, 150, and 200 mAs settings. Signal degradation due to radiation exposure was trivial for the 85, 125, and 250 mAs exposure setting. No signal degradation was observed for the 50, 100, and 150 mAs values.  
In the reproducibility investigation, the cold white LED strip was preferred because its C-V response to dose was outstanding among the tested LED strip colors. Further, the C-V signal was  
Figure 9: C–V signal reproducibility graphs based on (**a**) kVp, (**b**) mAs, (**c**) SID, (**d**) dose, (**e**) consistency, and (**f**) degradation variations.  
substantially reproducible, the least degraded, and the most consistent in comparison to other tested colors. The cold white C-V signal response to kVp, mAs and SID was also steady when compared to other LED strips colors. Likewise, in a study by [PERSON] (2018) that evaluated four commercial photodiodes for radiology dosimetry, the BPW34 photodiode was nominated to execute radiation-induced current measurements based on its reproducibility and repeatability.  
It is observed that graphs from Section 3.1 through 3.8 have noticeable statistical errors. This could be on account of the stability of the x-ray tube and LED chips, and the thickness of the depletion region (LED active area). Owing to variation of photon fluence striking the LED active area (under different SIDs) and the random interaction of x-ray photons, it remains questionable whether all the incident x-ray photons deposited within the depletion region create electrons which are then detected as C-V signals. This could also be a possible source of statistical errors in the graphs.