L2-4 <<
Previous Next >> L2-6
L2-5
Operational Procedures: Electrostatic Discharge
Another major safety hazard for computer systems and components is electrostatic discharge (ESD). ESD damage is caused by the discharge of static electricity that has been built up by the human body in the course of everyday events, such as walking, standing and sitting at our desks, and other activities. In drier (less humid) environments, static electricity builds up more quickly and becomes more of an issue. This is especially true during winter months. While static electricity cannot directly harm humans very much, it can be deadly to computer components. A person builds static electricity that can reach 20,000 to 25,000 volts, but is of a low amperage (making it safe for humans). When you touch something of lower electrical potential, such as the metal case of the computer or the circuit board of an expansion card, the static electricity in your body is discharged into that component, causing damage. If you touch a circuit board without taking ESD precautions, ESD may occur and cause permanent failure or an intermittent failure of the component.
計算機系統和組件的另一個主要安全隱患是靜電放電（ESD）。ESD損壞是由人體在日常活動過程中（例如走路，站立和坐在辦公桌旁以及其他活動中）積聚的靜電釋放引起的。在乾燥（濕度較低）的環境中，靜電積聚更快，成為一個更大的問題。在冬季尤其如此。儘管靜電不會直接對人類造成很大的傷害，但它可能對計算機組件造成致命的傷害。一個人積聚的靜電可以達到20,000到25,000伏，但電流強度很低（對人類安全）。當您觸摸電勢較低的物體（例如計算機的金屬外殼或擴充卡的電路板）時，體內的靜電會釋放到該組件中，從而造成損壞。如果在未採取ESD預防措施的情況下觸摸電路板，則可能會發生ESD，並導致組件永久性故障或間歇性故障。
You can protect computer equipment from ESD fairly easily. First, you should use an antistatic wrist strap, also known as an ESD strap.
您可以相當容易地保護計算機設備免受ESD的影響。首先，應使用防靜電腕帶，也稱為ESD腕帶。
These devices are very inexpensive and are the best method of protecting equipment against ESD. To be effective, one end of the strap must be grounded (by clipping it to something such as to the bare metal of the computer case), and the other end is placed around your wrist like a bracelet. This continually causes a discharge from the body to the computer case, thereby protecting the internal computer components. Because of the high voltage present inside a cathode ray tube (CRT) monitor, you should not wear an ESD wrist strap when working inside a CRT monitor.
這些設備非常便宜，是保護設備免受ESD影響的最佳方法。為使之有效，必須將腕帶的一端接地（通過將其修剪到諸如計算機機殼裸露的東西上），另一端像手鐲一樣放在手腕上。這連續地導致從身體向計算機機殼的放電，從而保護了內部計算機組件。由於陰極射線管（CRT）監視器內部存在高壓，因此在CRT監視器內部進行操作時，請勿佩戴ESD腕帶。
If you do not have an ESD strap, you can employ the second precautionary method, called grounding against the chassis. In this method, you touch any unpainted metal part of the computer case to discharge the static electricity from your body before touching the sensitive components (such as expansion cards). This method is quite good, but you must remember to ground yourself against the case every time before touching a component. The last precautionary method is to use anti-static bags. This procedure is useful during transport of various components. Basically, you place the components and cards inside the anti-static bag to protect them from ESD while you are carrying them from one location to another.
如果沒有ESD綁帶，則可以採用第二種預防方法，即與機箱接地。通過這種方法，在觸摸敏感組件（例如擴展卡）之前，請觸摸計算機機箱上任何未上漆的金屬部分，以釋放身上的靜電。這種方法相當不錯，但是每次觸摸組件之前，您都必須記住要使自己始終與外殼接觸。最後一種預防方法是使用防靜電袋。此過程在運輸各種組件時很有用。基本上，將組件和卡從一個位置搬運到另一位置時，請將其放置在防靜電袋中，以防靜電。
To prevent ESD we must ensure we handle components properly. Never touch the face of the cards where the components and wiring are located; only handle cards by the edges. Additionally, always use proper ESD straps or grounding techniques before handling the cards. You also should remove jewelry and avoid loose clothes, since they may get caught in the computer or inadvertently cause a static charge to be transferred into a component. Another great technique is the use of an anti-static mat or workbench. Many server rooms and IT shops have these mats installed, and they provide a good method of keeping yourself grounded while working. You can also raise the humidity of the room to minimize the chances of static build-up. Most computer server rooms keep humidity between 40 and 50 percent to minimize electrostatic build-up, but often you will not have control over the humidity as a technician. You also want to avoid carpeted areas when possible, as walking across carpet creates a faster buildup of static electricity in the body. Finally, never use electrical or magnetic tools on the workstation, as the electrical motors from drills, impact wrenches, and vacuums create static electricity that can be discharged into fragile components.
為了防止ESD，我們必須確保正確處理組件。切勿觸摸組件和配線所在的卡的表面；只能處理邊緣的卡。此外，在處理插卡之前，請始終使用正確的ESD腕帶或接地技術。您還應卸下珠寶首飾並避免穿寬鬆的衣服，因為它們可能會卡在計算機中或無意間導致靜電荷轉移到組件中。另一個很棒的技術是使用防靜電墊或工作台。許多服務器機房和IT商店都安裝了這些墊子，它們是在工作時保持接地的一種好方法。您還可以提高房間的濕度，以最大程度減少靜電積聚的機會。大多數計算機服務器機房將濕度保持在40％到50％之間，以最大程度地減少靜電積聚，但是作為技術人員，您通常無法控制濕度。您還希望盡可能避免舖有地毯的區域，因為在地毯上行走會在體內更快地積聚靜電。最後，切勿在工作站上使用電動工具或電磁工具，因為鑽頭，衝擊扳手和真空吸塵器產生的電動機會產生靜電，這些靜電會排放到易碎的部件中。
L2-4 <<
Previous Next >> L2-6