The tensile-strength test is innately damaging; during the process of collecting information, the sample is wasted. Although this is acceptable when a safe sample of the sample is available, nondestructive methods are safer for materials that are costly or hard to fabricate or that have been made into completed or semicompleted samples.
Liquids
One common nondestructive method, used to identify surface cracks and weaknesses in metal samples, takes a penetrating fluid, which needs to be visibly dyed or fluorescent. After being smeared on the surface of the metal sample and set to soak into any small imperfections, the liquid is rubbed away, leaving brightly perceptible cracks and imperfections. A similar method, better for nonmetals, takes an electrically charged liquid smeared on the sample surface. After superfluous liquid is removed, a dry powder of opposite charge is sprayed on the material and draws to the flaws. Neither of these techniques, however, can locate internal weak points.
Radiation
Internal, as well as external weaknesses, can be located by X-ray or gamma-ray technologies in which the radiation scans the metal and impresses on an appropriate photographic film. On some occasions, it may be possible to target the X rays toward a significant section within the piece, permitting a three-dimensional description of the flaw shape along with its site.
Sound
Ultrasonic inspection of areas takes transmission of sound waves above human hearing range through the sample. In the reflection method, a sound wave is sent from one part of the material, reflected off the far part, then signalled onto a receiver that is located at the original end. Upon finding a weakness or failure in the test sample, the signal is reflected and its movement altered. The actual delay is then a signal of the flaw’s location; a map of the piece can then be generated to show the point and shape of the weaknesses. In the through-transmission method, the transmitter and receiver need to be situated at the opposite ends of the test piece; delays in the signal of sound waves are utilized to target and measure cracks. More often than not a water medium is used by which transmitter, sample, and receiver will be immersed.
Magnetism
As the magnetic traits of a test piece are largely formed by its overall structure, magnetic methods are utilized to characterize the area and relative shape of flaws and cracks. With magnetic testing, an object is employed that consists of a big coil of wire through which flows a steady alternating current (primary coil). Held inside this larger piece is a smaller coil (the secondary coil), to which is attached an electrical measuring tool. The steady current in the initial coil makes current to react in the secondary coil by way of the method of induction. If an iron sample is put within the secondary coil, sudden changes in the secondary current should indicate imperfections in the bar. This technique only detects changes in zones within the length of a bar and cannot find elongated or continuous defects that easily. Another such process, using eddy currents induced with a primary coil, also can be used to find imperfections and cracks. A steady current is induced within the test sample. Cracks that are found within the track of the current alter resistance of the test material; this change will then be measured with the correct equipment.
Infrared
Infrared processes have also been employed to isolate material continuity in complicated structural items. While testing the quality of adhesive joints in the sandwich core and facing sheets within a usual sandwich construction sample such as plywood, for example, heat is applied in the face of the sandwich skin item. Where bond lines are found to be continuous, the core materials reveal a heat marking on the surface piece, and the local temperatures of the face should appear steadily along those bond lines. Where a bond line can be insignificant, gone, or mistaken, however, the local temperature will not drop. Infrared photography of the face will then isolate the location and area of the defective adhesive. Another such technique employs thermal coatings to change colour at reaching a specific temperature.
In conclusion, nondestructive testing techniques also are sometimes found to permit a whole determination of the mechanical characteristics of a test object. Ultrasonics and thermal processes seem to be the most valuable in this area.
Looking for NDT Brisbane? For Brisbane non-destructive testing, contact Just Inspections today.
Tags: brisbane, ndt, non-destructive testingApril 14th, 2010UncategorizedRead More >No Comments
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.
Tags: accountants, Australia, brisbane, collection, debt, payment cycles, queensland, small business, suppliersDecember 22nd, 2008UncategorizedRead More >No Comments
December 16th, 2008infomercialRead More >No Comments