How to select a radiography film viewer?



How to select a RT film viewer?

RT film viewers are known as Industrial Radiographic Illuminators. 

RT film viewer is used for identification and interpretation of industrial radiography films using transmitted light source. 

Radiography is one of the most important non destructive testing in construction industry. It is also one of the reliable methods in determining the corrosion rates and corrosion location determination as per API 570.

Radiography film viewers are needed for reviewing the radiography film. Here in this article we will discuss about selecting a suitable radiography film viewer and some available radiography film viewer manufactures. 

As you know we use different film sizes for industrial radiography. The film sheets for industrial radiography are most commonly supplied in 15" X 12" size (sheets can be purchased in any required size). These 15" X 12" film sheets are cut to different sizes to suite the job requirements minimising wastage. 

Some commonly used sizes are 5"L X 4"W, 6"L X 4"W, 7.5"L X 4"W, 12"L X 4"W, 15"L X 4"W . The width can be 3" also.  The selection of size depends on the size of the joint and maximum utilisation of a 15" X 12" film,

It can be seen that the maximum size required to cover a joint is of 4" width and the maximum length that can be cut from the sheet is 15". So we can come to a conclusion that 15" X 4" film is to be able to be viewed in the viewer.

The light area or technically we call it as viewing screen on the film to be 15" X 14". This viewing area is to be adjusted to view other small size films. 

You can select a smaller viewing area than this. At that time you have to move the film back and forth for reviewing bigger films.

The parts of a film viewer are 
1. Housing
2. Viewing Screen
3. Light,  Colour of light used to illuminate the radiograph shall be white.  Colour temperature between 5000 and 6250 deg.K.
4. Diffusing screen 
5. Anti-glare device or commonly known as  Pedal Switch


Some RT film Viewer manufacturers.
(Click on the images to visit the website of the manufacturers.)


Eastwest Engineering & Electronics Pvt.Ltd.




Arora Technologies (P) Limited (ATPL)

  



Reference : 
ASTM E1390-12, Standard specification for Illuminators used for viewing Industrial Radiographs. 


Disclaimer: Photos are taken from different websites. If this violates any copyright rules this will be removed. Please inform me if any of the photos or contents violates copyright rules. (through 13hareesh13@gmail.com). This blog is meant for educational purpose only. If it is used for any other means without the written consent from the author, the author will not be responsible. Author does not guarantee the accuracy of data used in this blog.All the information, data, photo/image, calculations presented in this blog should be used at the sole risk of the user. The blogger is not liable or responsible in any way for any damage, losses or costs arising from use of the blog for any purpose whatsoever or whosoever it may be. The blog is to be used at your sole risk and responsibility.





Comments