2021年1月17日 星期日

冬天裡的靜電 Static electricity in the winter


冬天天氣乾燥 ,當身體接近金屬物體,例如門鎖、水龍頭等,會產生微細「啪」的聲響,更甚在黑暗的環境中會看見閃光,皮膚亦會感到輕微刺痛 ,雖然一般不會對身體構成危害,但亦令人感到困擾。這種現象的成因是身體與衣服相互磨擦而積聚過多電荷(靜電),又因天氣乾燥,身體的電荷不能通過空氣洩放,聚積成為高電壓,形成高壓尖端放電,出現跳火。

靜電實在是一種有害現象,不單使人不快,更甚損害敏感的電子器材、電子零件等。所以在一些場所,要避免產生靜電就必須帶上除靜電的手帶,將靜電洩放至地端。(見圖   及圖   B

如人體不能避免產生靜電,一般家居最簡單的方法是在接觸金屬物體前,先用手(最好帶點濕潤)觸摸水泥牆壁   至   放電。因牆壁內阻較高,減低急速放電令高壓逐漸消失,此舉既可令身體放電,在放電時亦不會產生跳火

In winter air is often dry , when our bodies approach a metallic object, such as door lock, water tap, etc., we sometimes hear soft clicking sound, see little sparks in the dark even and we feel slight shock . Though this doesn’t cause hazard to our bodies, it is quite annoying. The reason behind is when you rub your skin and clothing against each other, electric charges (static electricity) accumulate in your body. However the electric charges cannot be discharged to ground in the dry air, high voltage is formed in your body and finally corona discharge happens, electric sparks appear .

Static electricity is an unpleasant phenomenon. Even worse, it can destroy electrostatic-sensitive devices and electronic components. Therefore in some occasions, we wear antistatic wrist strap to release electrostatic charges to ground. (See figure A and B)

If we cannot avoid static electricity, try to touch the cement wall with our hand (preferably it is moist or slightly wet skin) for 1 to 2 seconds before touching metallic objects. The high voltage will release slowly and pass to the earth by the cement wall, so the high voltage in your body will be gradually reduced. In this way, it won’t cause sparking. This is one of the simplest ways to safely remove static on human body at home.    




冬天裡的靜電 Static electricity in the winter

冬天天氣乾燥 ,當身體接近金屬物體,例如門鎖、水龍頭等,會產生微細「啪」的聲響,更甚在黑暗的環境中會看見閃光,皮膚亦會感到 輕微刺痛 ,雖然一般不會對身體構成危害,但亦令人感到困擾。這種現象的成因是 身體與衣服相互磨擦而積聚過多電荷(靜電),又因天氣乾燥,身體的電荷不能通過空...