All you need to know about test panels/ blocks used in Penetrant Inspection |
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Flaw detection with the help of liquid penetrant is being increasingly used in various industries. So, it is also important to check the system performance over a known specimen. As with penetrant inspection in general, results are directly dependent on the skill of the operator therefore there are some universal specimens that can be used if a reference part is not available. So here are some test panels which are typically used for checking the performance of penetrants. |
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NiCr Test Panel
NiCr test panel is a brass plate, which is plated with nickel & chrome of desired thickness uniformly. This panel is provided with parallel linear cracks on the plated layer by application of stretching stress in a direction perpendicular to the prospective direction of cracks. As it comes in pair & also known as Twin Nickel Chrome Constant Thickness Sensitivity Panel or Type 1 reference test block.
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NiCr panel is used to evaluate the sensitivity of inspection penetrant systems; both fluorescent & visible. They are especially effective in evaluating a penetrant systems ability to delineate shallow flaws. It is also used to compare new & used penetrant & can also be used for comparing performance of different penetrant materials or different processing techniques.
Available in versions with 10μm, 20μm, 30μm and 50μm crack depths.
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Crack Depth
50 μm
30 μm
20 μm
10 μm
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Sensitivity Level
1, 2, 3 & 4
2, 3 & 4
3 & 4
4
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Method Suitability
Color Contrast & Fluorescent
Color Contrast & Fluorescent
Fluorescent Only
Fluorescent Only
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How to increase the life of your NiCr Test Panel
- It should be cleaned to ensure that no residues are left on the panel.
- Ultrasonic cleaning with cleaner/remover solvent is recommended after use to remove all penetrant & developer material; after which it can be dried & wrap in a towel for storage.
- To avoid additional, uncontrolled cracking, do not flex or bend the panel or any kind of mechanical shocks.
- To remove flaw entrapped penetrant, immerse the panel in acetone/cleaner for several minutes with some agitation. To retard corrosion, do not soak the panel for long periods. Replace the solvent frequently.
- Do not expose the test panel to temperature over 100° C for an extended period, as these conditions will permanently damage the test panel.
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TAM Panel
TAM Panel is a stainless-steel panel, a strip of chrome plating runs the length of one side of the panel. Five crack centers are evenly spaced in the chrome plating. The crack centers are in raised circular patterns and are arranged in order of magnitude. They take a star or sunburst appearance. Adjacent to the chrome plating is an oxide grit blasted area, considered as medium roughness. It is also known as PSM-5.
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TAM Panels are used to test that all parts of a penetrant system are functioning correctly. It provides a fast and reliable means to check water washable, post emulsifiable, post removable, fluorescent or visible liquid penetrant inspection systems. It does not replace the NiCr panel.
The largest crack center has a diameter of about ¼ inch, the second largest 5/32 inch, the third 3/32 inch, the fourth 1/16 inch and the smallest about 1/32 inch.
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Level of sensitivity
Ultra-Sensitive Penetrant
High-Sensitive Penetrant
Medium-Sensitive Penetrant
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No of cracks seen for Fluorescent
Show all 5 cracks if all aspects are functioning properly
Reveal 4 cracks and, on occasion, the fifth and smallest crack.
Show the 3 largest crack centers and, on occasion, the 4th crack.
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Maintenance of TAM panel
- It should be dried after post cleaning as solvent residues repel and retard penetrant flaw entry.
- Use separate panels for each penetrant system.
- Maintain operation parameters. Do not short-cut panel processing, such as substituting a hand wipe for an oven dry.
- Clean immediately after test.
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Aluminium Comparator Block |
Aluminium Comparator Blocks are the two blocks of 50 mm × 35 mm x 10 mm of Aluminum alloy, which are cracked by heating them to very high temperature and quenching in water.
It’s used for comparing the performance of the penetrant and for comparison between two penetrants of different makes or batches. Comparison can be done with the pattern of crack indications and photographs provided.
The Aluminium comparator block is meant for one-time use as once the penetrants get into the cracks it is very difficult to clean hence it is recommended to use a new one if multiple comparisons are intended.
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Reference block Type 2 is made from stainless steel plated with a layer of nickel then a hard chromium alloy. Five star-shaped defects of ranging from 3.0 to 5.5mm diameters have then been artificially produced in this layer with the five defects uniformly placed according to their sizes.
Reference block Type 2 includes four adjacent patches with roughness of R = 2.5μm, 5μm, 10μm and 15μm. With the smallest defect being located next to the area showing the smallest roughness.
It is being used for routine assessment of the system performance of both fluorescent & colour contrast penetrant facilities and open containers. Block should not be kept in solvent & must be stored in a protective envelop to prevent scratching, twisting, any mechanical or thermal shock.
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FlawGlo Series of Liquid Penetrant Testing Chemicals |
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Salient Features:
- Vivid, high contrast color
- Low in Sulphur and halogens
- Good in Wettability, Viscosity & capillarity
- Superior flaw resolution
- Water washable and solvent type penetrant
- Excellent reliability
- High flash point
- Compatible with any metals & many synthetic materials
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Keeping the vision of “Make in India”, M/s. Arora Technologies (P) Limited (ATPL) is focusing on Manufacturing and Distribution of NDT Products & Accessories.
Our vision is to Innovate, design and manufacture NDT Products, Systems and Accessories for global markets by incorporating Quality & Excellence in our DNA. We are committed to build long-term relationships with our customers and pursue our business through innovation, latest technology & unrelenting quest for excellence.
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