| 摘要 |
A wearable digital air quality monitor, which can display the exact sampling of carbon monoxide (CO) and particulate matter (PM) data, and a program capable of performing the functions of sampling, interpreting the sampled data through an interpolation function on the sensors' response curve, controlling the heating element to the exact specifications of the metal oxide sensor, and calibration. Exposed to clean air environment, the CPU controls the heating element cycle to ensure a optimum sensor sensitivity to the CO and it then calibrates the sensor. In subsequent steps, the CPU samples and averages CO data taken at a predefined 50 millisecond interval and PM2.5 at a predefined 3 second interval, then determines the amount of carbon monoxide by performing an inverse logarithmic function that follows the sensor's response curve. For PM2.5 measurements, the data is normalized to determine a total particle count per centimeter cubed (cm3) and then applies a multiplier determining the PM2.5 density. This multiplier is based on air pollution studies conducted in North America and Europe. The CO and PM2.5 measurements are displayed on a dual-line BCD display. The device also has communication interfacing capabilities providing an external link to other computers, hand-held devices such as smartphones and tablets. |
