I need to know what are the prerequisites for being a recognized NDT tester for Concrete. I am a fresher B.Tech Civil Engineer from India. My current knowledge in NDT consists only of Rebound Hammer Test (Schmidt's Hammer), Ultrasonic Pulse Velocity Test and Core Drilling Test which I performed during my internship.

If anyone is experienced in this field or has the knowledge about it, kindly help me find answers to these questions. Any help would be appreciated.

1. What academic qualification is required to be an independent tester ? (If any, apart from B.E./B.Tech.)

2. Are there any extra certifications/courses required ?

3. Do I need to possess a certain level of experience in the field before I can start testing independently ?

4. Which are the most widely used tests in an infrastructure or industrial project ?

5. Which Standards should I refer for these tests ? (As of now I have only referred IS 13311 part 1 and 2 for Rebound Hammer and UPV tests). In some cases we also refer codes other than Indian Standards so I am open to those as well. Basically I want to know the codes that are accepted by the industry.

If any of you know someone who might be able to help me and isn't available on Reddit, I am fine with contacting them on other platforms like LinkedIn, etc.

Olight Warrior Mini 2 in the dirt

Ah the long awaited Olight Warrior Mini 2 . I want to take a slightly different approach for this writeup. usually I just spew my off the cuff thoughts into the post but for this one we have a bit of a unique case, given the storied history of the Warrior Mini.

Storied is just a fancy for word for fiasco. To recap: The Warrior Mini was introduced and everyone loved it. Even renowned Olight haters like u/zak were forced to admit that it had no competition at the time. Filling the unique role of a purpose designed EDC light with a tactical/ self defense bent, it came very close to achieving it. I reviewed it here and was overall positive about it

A short while after launch, a problem cropped up. People had holes in their pockets. The Warrior Mini was to blame and everyone sharpened their pitchforks. Olight recognized the issue, took the position that it is a user error, and launched a voluntary return program for full refund (or for those that choose to keep the Warrior Mini, silicon tail cap and free Olight obulb). The return program launch was not without hiccups, no damage control at this scale is. But that’s not what this post is about so lets get back to the light.

https://preview.redd.it/a1w8wrd1yh571.jpg?width=3024&format=pjpg&auto=webp&s=d68bc8bde4e2decd4943e23e4c4752533f32b128

Rather then offering the bandaid and closing the book on the issue, Olight redesigned the entire light into the Warrior Mini 2. I’m glad they did, it’s a unique light with unique features and very useful. This post is going to be about the design improvements and some of my opinions on them. As usual, I don’t really publish spec tests in my posts, I leave that up to the experts. Also, links in the post are all aff links and Olight sent me this light for free because I'm PhotonPhreaks

https://preview.redd.it/208t6y7wvh571.png?width=624&format=png&auto=webp&s=63388b1e

Non destructive Testing (NDT)- Common Methods are:

1. Visual Inspection – VT
2. Liquid Penetrant Testing – LT
3. Magnetic Particle Testing – MT
4. Radiographic Testing – RT
5. Ultrasonic Testing – UT

1.   Visual Inspection – VT:

Visual inspection after welding is very useful in evaluating quality, even if other testing methods are to be employed. As welding progresses, surface flaws such as cracks, porosity, and unfilled craters can be detected only by Visual Inspections, leading to repairs or rejection of the work.

Welds must be cleaned from slag to make inspection for surface flaws possible. A 10x magnifying glass is helpful in detecting fine cracks and other faults. As indicated before, a borescope and dental mirrors, are useful for inspection inside vessels, pipe, or confined areas.

Visual inspection is the most popular and the most widely used of the non-destructive inspection techniques. Completed welds should be checked according to the plans and the specifications.

The most common welds that need to be inspected in the field are fillet welds. Fillet welds are designed based on their leg sizes. If the leg is under the specified dimension, then the strength required is less than what the joint was designed for. The throat of the weld should be checked also.

Inspector visual requirements: Performed with or without corrective lenses, to prove near vision acuity on Jaeger J2 at not less than 12 inches and a color perception test. The objective of visual inspection at this stage is not only to detect non permissible faults, but all procedure details.

If the plans show a fillet weld at 5/16 inches then each leg of the weld needs to measure to that dimension. A fillet weld gauge is the standard tool to check weld sizes.

2.   Liquid Penetrant Testing – LT:

Liquid Penetrant inspection methods are used to check nonporous materials for defects open to the surface and surface defects can be found with penetrant inspection. Several types of cracks connected with seam welding, grinding, porosity or lack of bond between metals, this method can locate.

The equipment used in Liquid Penetrant Testing is portable: aerosol cans of cleaner, dye, and a developer. When fluorescent penetrant is used, a black light source in the 36-angstrom unit range and a hood or dark area are required. Portable inspection kits for field use are commercially available.

The procedure conforms to ASTM E 165. There are three types of penetra

In our lifetime we all come across few old, beautiful, but damaged building that needs enhancement. But, do you know structural engineers need to know the compressive strength of the concrete before planning any changes in such buildings? The Windsor Probe Testing is used to evaluate the compressive strength of the concrete. Let's learn how it is a non-destructive method to measure concrete strength here - https://concreteinsight.com/windsor-probe-testing-a-non-destructive-method-to-measure-concrete-strength/

https://preview.redd.it/t7ymzuwc0jf71.jpg?width=2245&format=pjpg&auto=webp&s=5df4f1256703fadb1d194d2a0ff8e05b6e5339df

I've built a [crowbar circuit]( https://en.wikipedia.org/wiki/Crowbar_(circuit) ) to put on my old C64 power supply to prevent the dreaded 12V "brick of death" failure mode that fries all the sensitive almost-irreplaceable chips in C64s.

I don't have an oscilliscope, and I'm not really keen on buying a "cheap" $100 one that I have to plug into a laptop, and that I'll almost never have a use for otherwise.

Thought occurs to me all I really need is a handful of chips that will die when exposed to 7 volts. ( like the C64's old chips).

Can anyone suggest any cheap common chips or classes of chips that aren't expensive that would be suitable for "destrutive testing" to see if my circuit responds fast enough to a 12V surge to protect them?

I think the important thing is that they:

• are cheap
• die with even a little over-voltage, like the C64's sensitive chips.
• are easy to test good/bad

Related to that last point, I actually have 20 or so 64k 1bit MN4164P-15A DRAM's pulled from an old 8088 PC Compatible - but that's DRAM. For an amateur like me - testing whether it is operating properly is not as simple as say a quad-NAND or something.

I was interested in the area of non destructive testing. In order to get an ASNT NDT Level 3 certification you dont need a college degree but you do need 4 years of experience if you dont have one. Is there a way for an A&P to gain that experience somehow?