| 摘要 |
<p>The present invention relates to a portable device for displaying the level of room air on a real time basis, comprising a dust sensor which measures the concentration of fine dust inside with use of a sensor voltage whose voltage range is between 4.5 and 5.5; an LED display part which consists of a plurality of LEDs with different colors; a temperature and humidity display part which is physically separated from the LED display part to display temperature and humidity; and a control part which displays the concentration of the fine dust measured by the dust sensor by classifying the concentration in a plurality of levels with use of a PWM pulse width via the LED display part on a real time basis.</p> |
