在使用工業內窺鏡檢測前,應注意提前了解產品的性能參數、使用環境、檢測工況、被檢測目標等具體情況,方能實現更好的檢測效果。影響工業內窺鏡檢測效果的幾個主要因素有:
Before using industrial endoscope for testing, we should pay attention to understand the specific conditions of product performance parameters, use environment, testing conditions, tested targets and so on in advance, so as to achieve better testing effect. Several main factors affecting the detection effect of industrial endoscope include:
1、照明條件(光源)
1. Lighting conditions (light source)
內窺鏡檢測大多使用內窺鏡自帶光源進行照明。一般條件下,要求內窺鏡檢測照明光源色溫不低于5600K,照明強度不低于2600lm。工業內窺鏡一般有前置和后置兩種照明方式。前置照明是通過將數顆LED燈珠集成于探頭前端,這種方式成本較低,而且壽命短、容易損壞。后置照明則是通過導光光纖,將內置于主機的LED光源傳導到前端用于照明。這種照明方式大大提高了照明亮度,而且壽命較長。目前主流的高端電子視頻內窺鏡大部分采用后置導光。
Endoscope detection mostly uses its own light source for illumination. Under normal conditions, the color temperature of the lighting source detected by the endoscope is required to be no less than 5600k, and the lighting intensity is required to be no less than 2600lm. Industrial endoscopes generally have two lighting modes: front and rear. The front lighting integrates several LED light beads into the front end of the probe, which has the advantages of low cost, short service life and easy damage. The rear lighting transmits the LED light source built in the host to the front end for lighting through the light guide fiber. This lighting method greatly improves the lighting brightness and has a long service life. At present, most of the mainstream high-end electronic video endoscopes use rear light guide.
2、探頭位置與角度
2. Probe position and angle
通常在距離檢測區域5~25mm范圍內觀察圖像的效果 ,因此往往需要內窺鏡探頭盡量靠近觀測點。探頭與觀察物平面在45゜~90゜范圍內都可以達到較好的觀察效果,在實際工作中是通過反復改變探頭與觀察點的位置與角度找到合適的觀察位置,并獲得的檢測效果。
Generally, the effect of observing the image within 5 ~ 25mm from the detection area is the best, so the endoscope probe is often required to be close to the observation point as far as possible. The probe and observation object plane can achieve good observation effect in the range of 45 ゜ ~ 90 ゜. In practical work, it is through repeatedly changing the position and angle of the probe and observation point to find the appropriate observation position and obtain the best detection effect.
3、檢測通道
3. Detection channel
探頭可以通過狹小、彎曲的通道進行檢測。選擇通道時應了解通道的情況,檢測時盡量靠近需要檢測位置,選擇進入長度短的通道,盡量減少探頭需要彎曲的次數及程度;考慮由上到下,由高到低的通道;優先選擇寬闊的通道;使用輔助工具(如居中器等),保證探頭在產品通道中的正確方向;應采用邊觀察邊通過的方法在通道中行進。
The probe can be detected through narrow and curved channels. When selecting the channel, first understand the situation of the channel. When testing, try to be close to the position to be tested, and select the channel with the shortest entry length to minimize the number and degree of bending of the probe; First, consider the channel from top to bottom and from high to low; Give priority to wide channels; It is recommended to use auxiliary tools (such as centering device) to ensure the correct direction of the probe in the product channel; The method of observing while passing shall be adopted to walk in the channel.
4、圖像畸變
4. Image distortion
內窺鏡的圖像畸變是通過透鏡觀察物體產生的變形現象,隨著從透鏡中心到邊緣距離的增大,圖像形態會發生改變。圖像的畸變會對缺陷的判斷及測量產生影響。直桿鏡、光纖鏡觀察時圖像的畸變較大,視頻內窺鏡可通過計算機進行較正。
The image distortion of endoscope is the deformation phenomenon caused by observing the object through the lens. With the increase of the distance from the center to the edge of the lens, the image shape will change. Image distortion will affect the judgment and measurement of defects. When observing with straight rod mirror and optical fiber mirror, the image distortion is large, and the video endoscope can be corrected by computer.
5、圖像分辨率
5. Image resolution
圖像分辨率指圖像中存儲的信息量,是每英寸圖像內有多少個像素點,分辨率的單位為PPI(Pixels Per Inch),通常叫做像素每英寸。圖像分辨率一般被用于ps中,用來改變圖像的清晰度。圖像分辨率越高圖像越清晰。圖像分辨率是內窺鏡自身重要技術指標,可直接影響到探測的結果。
Image resolution refers to the amount of information stored in the image, which is the number of pixels per inch of the image. The unit of resolution is PPI (pixels per inch), which is usually called pixels per inch. Image resolution is generally used in PS to change the definition of the image. The higher the image resolution, the clearer the image. Image resolution is an important technical index of endoscope itself, which can directly affect the detection results.
6、圖像放大倍數
6. Image magnification
圖像放大分為光學變焦和數碼變焦,前者通過改變焦距,放大圖像不改變清晰度,后者則是利用軟件放大,相當于通過軟件處理對已有像素周邊的色彩進行判斷,根據周邊的色彩情況插入經特殊算法加入的像素,這種情況下放大倍數越高會使圖像更模糊。
The higher the resolution of the image by adding the digital zoom algorithm, the higher the resolution of the surrounding image will be determined by adding the digital zoom algorithm, and the image will be divided into the blurred image by adding the digital zoom software. In this case, the higher the resolution of the surrounding image will be determined by adding the digital zoom algorithm.
7、可檢測小缺陷
7. Minimum detectable defects
可檢測小缺陷則與圖像清晰度、測量精度等指標密切相關。
The smallest defect that can be detected is closely related to image clarity, measurement accuracy and other indicators.
8、物體表面的反射率
8. Reflectivity of object surface
不同的物體表面有不同的反射率,和物體的材料和表面的粗糙程度都有關系。在實際檢測中,有些較為光亮的反射面,在亮度較高時反而難以實現較為準確的檢測效果。因此實際檢測工作中應該根據具體的情況選擇內窺鏡照明的強度以便得到清晰有用的結果。一般情況下工業內窺鏡都具有多級照明調節功能,有部分產品則會采用軟件控制自動調光,可以根據環境進行調整照明亮度。
Different object surfaces have different reflectivity, which is related to the material and surface roughness of the object. In the actual detection, some brighter reflecting surfaces are difficult to achieve more accurate detection effect when the brightness is high. Therefore, the intensity of endoscope illumination should be selected according to the specific situation in the actual detection work, so as to obtain clear and useful results. Generally, industrial endoscopes have multi-level lighting adjustment function, and some products will use software to control automatic dimming, which can adjust the lighting brightness according to the environment.
具體情況還往往需要現場進行測試,以實際和理論相結合方可選擇更為適用于實際工況的內窺鏡產品
Specific conditions often need to be tested on site, and endoscope products more suitable for actual working conditions can be selected only by combining practice and theory