## 3 Results and Discussion
### Analyzing of Recorded Data  
Given that the statistical dispersion of measurements of a quantity under identical circumstances defines precision, the standard deviation calculated from each sensor's readings is steady and repeatable. The standard deviation is a metric used to assess how dispersed data are in relation to their average value; a larger range for this parameter indicates a higher degree of measurement uncertainty. However, data from all sensors were subjected to descriptive statistical analysis to obtain the mean, minimum, maximum, standard deviation (SD), and coefficient of variation (CV, %). The percentage value of CV was categorized as low (CV \(<12\%\)), medium (if CV = 12-24%), and high (when CV \(>24\%\)) [33]. However, the average values for air temperature, relative humidity, atmospheric pressure, air dust concentration, and carbon monoxide concentration are displayed in Table 1 for the different sites. Meanwhile, Table 2 shows the maximum and minimum values, the coefficient of variation, and the standard deviation of these data on the variables of carbon monoxide concentration (CO) and dust concentration in the air (DC). Figure 4: Relationship between the readings of air relative humidity from the developed device and the Testo 625 device. It is clear from Table 1 that the overall average dust concentration in the air and carbon monoxide concentration recorded at different sites were respectively 233.6 \(\mathrm{\SIUnitSymbolSymbolMicro m^{3}}\) and 11.6 ppm. In addition, the overall average of air relative humidity, air temperature, and atmospheric pressure were respectively 23.8%, 34.1 \(\mathrm{\SIUnitSymbolSymbolCelsius}\), and 895.3 hPa. Furthermore, low air relative humidity (<30%) can affect human health [46]. Moreover, the overall average CO value was 11.6 ppm (Table 1); the obtained CO level in this study was at a bad level according to [PERSON] et al. [47], who stated two levels of CO, normal in the range of 0.0-9.0 ppm and bad in the range of 9.1-15.0. In the study of [PERSON] et al. [11], they recorded values of 28.38 ppm and 35.40 ppm in a residential area using an MQ7 sensor connected to an Arduino board for detecting CO concentration using two sensors. Additionally, on the main road (commercial area), the averages of 44.10 ppm and 35.40 ppm for CO concentration were detected by these two sensors. The duration of monitoring measurements of [PERSON] et al. [11] study was set at 3 min. The overall average dust concentration in the air in this study was 233.6 \(\mathrm{\SIUnitSymbolMicro m^{3}}\) (Table 1); however, particulate matter exposure is generally considered hazardous and dangerous because of the potential for some negative health effects, including irritation of the eyes, nose, and throat, worsening of symptoms associated with respiratory and heart diseases, and even an increased risk of premature mortality in individuals with  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Site Symbol**} & **Air Relative** & **Air** & **Atmospheric** & **Dust Concentration** & **Carbon Monoxide** \\  & **Humidity** & **Temperature** & **Pressure** & **in the Air** & **Concentration** \\ \cline{2-6}  & **(\%)** & **(\(\mathrm{\SIUnitSymbolMicro C}\))** & **(hPa)** & **(\(\mathrm{\SIUnitSymbolMicro m^{3}}\))** & **(ppm)** \\ \hline F1 & 39.5 & 21.4 & 945.7 & 167.7 & 13.8 \\ F2 & 28.9 & 27.8 & 944.7  
lung or heart illness [48]. So, several authorities have published recommendations for permissible limits for particulate matter in the air. The recommended level of PM10 was identical by 50 ug/m\({}^{3}\) and not to be exceeded more than 35 times a year with an annual average limit of 40 ug/m\({}^{3}\)[49]. The World Health Organization also recommended a limit of PM2.5, which is 25 ug/m\({}^{3}\)[49].