如今，行業比以往任何時候都需要不斷開發和實施良好的質量控制程序。無論產品如何，質量和可靠性的重要性都是至關重要的。拒絕花費時間，金錢，并有可能破壞長期客戶關系。因此，每次質量檢查都必須正確。便攜式紫外線黑光燈正在許多不同行業中迅速增加使用和接受，從而大大改善了質量控制。
紫外線的定義和分類
紫外線（UV）代表整個電磁光譜的一部分，從可見光的藍色端（400 nm）延伸到X射線區域（100 nm）。
按照光能的增加順序，將其細分為三個不同的波長區域，分別描述為UV-A，UV-B或UV-C。
UVA（400 nm – 315 nm）：通常稱為“黑光”，這是最長的波長區域和更低的能量，它代表了天然UV光的更大部分。大多數紫外線熒光檢查過程都使用這種紫外線。
UVB（315 nm – 280 nm）：比UV-A更高的能量，通常被稱為中波或紅斑紫外線。這部分被臭氧層阻擋，是自然紫外線的最侵蝕性成分，在很大程度上導致了曬傷（紅斑）。
UVC（280 nm – 100 nm）：比UV-A和UV-B高的能量。它通常被稱為短波或殺菌紫外線。由于人造紫外線被地球大氣吸收，因此通常僅在人造紫外線光源中遇到。
紫外線誘導的熒光的定義
紫外線光子提供的激發能比生理溫度下吸收分子（例如紫外線熒光顏料）的熱運動能高得多。因此，吸收分子暫時具有較高的能級。隨著被激發的電子隨后返回到較低的高能態，其多余的部分將作為光子發射被處置掉，從而產生熒光。與激發紫外線相比，熒光通常通過更長的波長來識別。
在質量控制熒光檢查過程中使用紫外線黑光分為兩個不同的類別：
紫外線熒光檢查過程是在紫外線黑光下結合紫外線熒光材料或可見/不可見紫外線的顏料進行的。其中包括NDT裂紋檢測；檢測流體泄漏并驗證材料擴散。
在紫外線黑光下進行的紫外線熒光檢查過程利用了材料的自然熒光特性。一個典型的例子是檢測碳氫化合物的污染，例如氧氣容器和連接管道中的油脂。
用于檢測裂紋的無損檢測（NDT）
這也許是紫外線黑光熒光檢測泛使用的應用。該過程依賴于通過紫外熒光磁性顆粒或染料滲透劑突出缺陷。這些可能是發際線裂縫，例如飛機起落架，汽車轉向系統和我們賴以生存的許多其他關鍵部件。
與可選的色彩對比方法相比，此過程提供了更高的靈敏度。這是由于缺陷的明亮發光圖像與黑暗環境之間的巨大反差，這確保了被檢查表面的其余部分實際上消失了。結果更容易，檢查更快。這些指示字面意義上是從操作員那里跳出來的，而不是相反的，檢查員正在尋找缺陷或間斷的視覺圖像。結果是增加了發現缺陷的可能性。
該工藝泛地用于航空航天和汽車工業，在選擇和操作UV黑光燈時必須小心以確保符合所有相關標準。這些與UVA光輻照度的最小級別和更大允許可見光級別有關。
便攜式黑光燈用于無損檢測
流體泄漏檢測
與NDT裂紋檢測過程相似，因為它還依賴于顏色對比限定條件，因此靈敏度得到了類似的提高。將紫外線熒光泄漏檢測添加劑與所涉及的流體系統混合，包括水，油，燃料，冷卻劑和制冷劑。設備正常運行，以使熒光添加劑循環流通。然后，通過在紫外線黑光下檢查所有外表面，管道，接頭，線圈等，任何泄漏將顯示為明亮的熒光黃綠色輝光。
此過程可用于常規質量控制或故障排除過程。典型的應用包括：-
汽車，包括發動機，變速箱，動力轉向，液壓，冷卻和空調系統
空調和制冷設備
工業廠房及機械
便攜式黑光燈用于液體熒光檢漏
清漆材料分散驗證
例如，電子印刷電路板上的透明涂層和金屬被廣泛用于保護和裝飾目的。這些透明涂層通常是在配方中加入不可見/可暴露紫外線的顏料。在將涂料施涂到基材上后，紫外線黑光檢查將確認保形涂料分散液的均勻性或選擇性放置涂料的準確性。
便攜式黑光燈用于pcb板三防漆涂敷檢查
氧氣清潔度驗證，用于檢測容器和連接管道中的碳氫化合物
最小量的碳氫化合物污染，例如氧氣容器或連接管道內的油或油脂，將導致災難性后果。它實際上是一種爆炸性混合物。
許多碳氫化合物會在紫外線黑光下自然發出熒光，因此，此過程對于所有氧氣容器和工廠的制造商及用戶都是必要的。
便攜式黑光燈用于氧氣管道脫脂清洗檢查
UV blacklight fluorescent inspection processes improve quality control
Today, industry has a great than ever need for continuous development and implementation of good quality control procedures.
The importance of quality and reliability, whatever the product, is paramount. Rejects cost time, money and have the potential to damage long term customer relationships. Therefore quality checks must be right first time, every time.
UV light fluorescent inspection processes are finding rapidly increasing use and acceptance across many different industries, resulting in dramatically improved quality control.
Definition and classification of UV light
Ultra Violet (UV) light represents a section of the overall electromagnetic spectrum of light, extending from the blue end of the visible (400 nm) to the x-ray region (100 nm).
It is subdivided into three distinct wavelength regions described as either UV-A, UV-B or UV-C in increasing order of photo energy.
UVA (400 nm – 315 nm): Often referred to as ‘blacklight’, this is the longest wavelength region and lowest energy, it represents the largest portion of natural UV light. It is this type of UV light which is utilised by most UV light fluorescent inspection processes.
UVB (315 nm – 280 nm): Higher energy than UV-A and often referred to as middlewave or erythemal UV light. Partially blocked by the ozone layer, this is the most aggressive component of natural UV light and largely responsible for sunburn (erythema).
UVC (280 nm – 100 nm): Higher energy than UV-A and UV-B. It is often referred to as shortwave or germicidal UV light. Only generally encountered from artificial UV light sources since it is totally absorbed by the earth’s atmosphere.
Definition of UV light-induced fluorescence
The excitation energy provided by UV light photons is much higher than the energy of thermal motion of the absorbing molecules e.g. UV fluorescent pigments at physiological temperatures. Consequently, the absorbing molecules temporarily assume higher energy levels. As an excited electron subsequently returns to a lower energetic state, its excess is disposed of as a photon emission, resulting in fluorescence. Fluorescent light is recognised by its usually longer wavelength compared with the exciting UV light.
The use of UV blacklight for quality control fluorescent inspection processes are split into two distinct categories:
UV Fluorescent Inspection processes performed under UV blacklight in conjunction with UV fluorescent materials or invisible/UV revealing pigments incorporated. These include NDT crack detection; detection of fluid leaks and material dispersion validation.
UV Fluorescent Inspection processes carried out under UV blacklight which utilises the natural fluorescent properties of materials. A typical example is the detection of hydrocarbon contamination such as oil and grease in oxygen vessels and connecting pipework.
Non-destructive testing (NDT) for the detection of cracks
This is perhaps the most widely used application of UV blacklight fluorescent inspection. The process relies on highlighting defects by UV fluorescent magnetic particles or dye penetrants. These can be hairline cracks for example in aircraft landing gear, automotive steering systems and many other critical components upon which our lives may depend.
This process offers greater sensitivity in comparison to alternative colour contrast methods. This is due to the dramatic contrast between the bright glowing image of a defect and the darkened environment, which ensures the virtual disappearance of the remainder of the surface under inspection. The result is easier, more rapid inspection. The indications literally jump out at the operator, rather than the opposite, where the inspector is seeking the visual image of the defect or discontinuity. The result is an increased probability of detection of defects.
The process is most widely used in the aerospace and automotive industries, where care must be taken when selecting and operating UV blacklights to ensure absolute conformance to all relevant standards. These relate to minimum levels of UVA light irradiance and maximum permissible visible light levels.
Fluid leak detection
Similar to the NDT crack detection process because it also relies on colour contrast qualifications and therefore offers similar sensitivity improvements. A UV fluorescent leak detection additive is mixed with the fluid system in question, including water, oils, fuels, coolants and refrigerants. The equipment is operated as normal to allow the fluorescent additive to circulate throughout. Then, by inspection under UV blacklight of all external surfaces, pipework, joints, coils etc, any leak will be revealed as a bright fluorescent yellow-green glow.
This process can be used for routine quality control or troubleshooting procedures. Typical applications include:-
Automotive, including engines, transmissions, power steering, hydraulic, cooling and air conditioning systems
Air conditioning and refrigeration equipment
Industrial plant and machinery
Clearcoat material dispersion validation
Clear coatings on electronic printed circuit boards and metals, for example, are widely used for protective and decorative purposes. These clear coats are often formulated with the inclusion of an invisible/UV revealing pigment. After application of the coating to the substrate, UV blacklight inspection will confirm the uniformity of conformal coating dispersion or accuracy of selective placement of coating material.
Oxygen cleanliness validation for detection of hydrocarbons in vessels and connecting pipework
The smallest amount of hydrocarbon contamination, such as oil or grease within an oxygen vessel or connecting pipework will result in catastrophic consequences. It is literally an explosive mixture.
Many hydrocarbons will naturally fluoresce under UV blacklight and therefore this process is absolutely essential for all oxygen vessel and plant manufacturers and users.
