Aussie Web Directory

April 14, 2010

Types of Non-Destructive Testing

Filed under: Interesting — Tags: , , — Bradley Fraser @ 7:34 pm

The tensile-strength test is innately fruitless; during the process of gathering research, the sample is ruined. While this is excusable when a safe supply of the material exists, nondestructive tests are desirable for materials that are expensive or difficult to fabricate or that have been shaped into finished or semicompleted samples.

Liquids

One common nondestructive method, employed to detect surface cracks and flaws in samples, uses a penetrating liquid, which is either brightly coloured or fluorescent. After being rubbed on the surface of the metal sample and left to sink into any perceptible markings, the dye is cleared, leaving totally perceptible breaks and flaws. A similar test, used for nonmetals, requires an electrically charged liquid painted on the material surface. After excess fluid is cleaned off, a dry powder of opposite charge is sprayed onto the nonmetal and sinks into the breaks. Neither of these processes, however, can detect internal flaws.

Radiation

Internal, like external imperfections, can be detected with X-ray or gamma-ray machines in which the radiation passes through the sample and impresses on a suitable photographic film. On some occasions, it may be possible to focus the X rays toward a single section in the piece, creating a 3D perspective of the flaw markings along with its site.

Sound

Ultrasonic inspection of areas involves transmission of sound waves out of human hearing range through the test sample. In the reflection method, a sound wave is transmitted over one part of the material, reflected off the far part, then signalled into a receiver that is located at the beginning side. By impinging on a mark or imperfection in the piece, the sound wave is reflected and its signal altered. The actual delay is a sign of the location of the mark; a map of the test material can be generated to reveal the point and form of the marks. Using the through-transmission method, the transmitter and receiver are situated on opposite areas of the subject; delays in the passage of sound waves are found to isolate and measure weaknesses. More often than not a water medium is employed by which transmitter, sample, and receiver should be immersed.

Magnetism

As the magnetic characteristics of a test piece are very much shown by its overall structure, magnetic techniques are sometimes employed to measure the situation and approximate dimensions of failures and marks. For magnetic testing, an object is employed that contains a big length of wire through which flows a steady alternating current (primary coil). Placed within this larger wire is a shorter coil (the secondary coil), to which is connected an electrical measuring device. The steady current in the first coil forces current to react in the secondary coil by way of the technique of induction. If an iron rod is inserted in the secondary coil, acute changes in the further current can signal defects in the piece. This process only finds differences within sections in the length of a piece and cannot find elongated or continued imperfections very much. A similar technique, utilizing eddy currents induced with a primary coil, also may be used to detect imperfections and cracks. A steady current is induced within the test object. Marks that lie within the signal of the current determine resistance of the test material; this alteration should be measured by better tools.

Infrared

Infrared processes have sometimes been utilized to detect material continuity in intricate construction materials. By testing the quality of adhesive joints in the sandwich core and facing sheets with a usual sandwich structure material such as plywood, for example, heat is the surface of the sandwich skin piece. In the case that bond lines appear to be continuous, those core samples reveal a heat marking on the surface material, and the localised temperatures of the surface should spread lightly along those bond lines. In the case that that bond line can be insignificant, missing, or erroneous, however, temperature should not adapt. Infrared photography of the front does isolate the situation and geometry of the failing adhesive. Another such process uses thermal coatings that change appearance when reaching a specific heat.

Finally, nondestructive methods also are being seen to allow a total determination of the mechanical elements of a test sample. Ultrasonics and thermal processes seem to be the most trustworthy in this circumstance.

Looking for NDT Brisbane? For Brisbane non-destructive testing, contact Just Inspections today.

Sphere: Related Content

December 21, 2008

Good Reasons to Pay Your Suppliers on Time

Filed under: Interesting — Tags: , , , , , , , , — Bradley Fraser @ 10:30 pm

Many small businesses spend far too much time on debt collection rather than their core business. Over the last 2-3 months I’ve noticed an increasing lag in payment cycles.

If you are in any sort of operation that uses small businesses as service providers or product suppliers it’s well worth your while to pay your bills on time and completely ignore to some “clever” accountants mantra of not paying until the second reminder. Guess what? People are human and they will pay back and pay forward. One way or the other you will pay in the end for screwing around your suppliers.

Here’s why:

1. If you pay on time you will get much better service. I know with my clients, the one’s who pay on time or early get the best service, day or night 365 days per year. These are A-Class clients. They pay on time or early, don’t bitch about the price, and as a result get excellent service and great value for money. They respect me, and I respect them. We both win.

2. If you don’t pay on time you reputation is on the line. Small business owners love to gossip. They slag off any customers who pay late. And with the Internet so freely available, your reputation can become crap overnight with one blog post. This leads into …

3. If you don’t pay on time, you can end up paying a premium. The current cost of money is about 1.5% per month. If your payment reputation is shite, than expect to pay at least 10-15 % more than if it were good or unknown. In some cases bad payers can be locked out of they supply chain completely and have to spend enormous amounts of time to find a new supplier.

With existing suppliers, if you screw them around, they will either add 10% to their next quote, or refer you to a lower-class competitor - hoping to send them broke because you don’t pay when due.

4. If you pay on time your staff don’t get harassed by debt collectors from your supplier’s accounts departments. This is a big source of staff burn-out. If you pay on time your staff won’t have to make up excuses for late payment and may actually start to enjoy their jobs.

In summary, if you want good service, good products, happier staff and ongoing loyalty, pay on time or before time and ignore your accountant’s advice.

What do you think? Why do you like early payment or not?

==========

Article supplied by Brisbane web designer and SEO Training.

Sphere: Related Content

December 16, 2008

Laser Hair Removal Brisbane

Filed under: Interesting — Tags: , , , — Bradley Fraser @ 6:44 pm

 

 

Brisbane Laser Hair Removal

Powered by WordPress