The use of X-ray-based nondestructive test methods dates back more than a hundred years, with the advent of film-based radiography. This article describes a number of X-ray-based offerings for today’s nondestructive testing applications.
Traditional measurement of surface texture using 2-D profilometers has major limitations. It gives satisfactory results for isotropic surfaces that present identical features regardless of the direction of measurement. The method also can be applied to some anisotropic surfaces in accordance with ISO 4288, such as turned surfaces with representative profiles that are perpendicular to tool marks. But it does not provide a general solution.
Quality procedures are put in place to document materials as they are received and as they move through the production process, but what happened to those raw materials before they arrived at the receiving dock? This was the problem facing St. Cloud, MN-based DCI Inc., a manufacturer of stainless steel and nickel alloy vessels and equipment.
Must quality engineers and product managers always be at odds? The former seeks perfection while the latter pushes for greater throughput. With the latest improvements in leak detection devices, both agendas can be served, as the best examples of this testing equipment help speed the quality control process without sacrificing accuracy.
Acceptable product performance is the ultimate goal of any manufacturer. This requires not only well-controlled material input and process control for making acceptable products, but also a way to ensure that, when products are used where failure could be dangerous or expensive, a screening method ensures the rejection of unacceptable products. Performance-based screening using NDT is an approach to guarantee that high-performance, quality parts are shipped to the customer.
Infrared thermography is the science of detecting and measuring variations in heat emitted by an object and transforming them into visible images. It is a rapidly developing technology for nondestructive testing (NDT) in many applications. Recent advances in imaging equipment allow for more rapid data acquisition and higher spatial resolution, thus opening up new areas of application.
The Maxima ML-3500 Series ultraviolet lamps use advanced micro discharge light (MDL) technology plus a filter and bulb/reflector to deliver up to 10X the UV-A output of conventional HID inspection lamps. With these lamps, NDT inspectors can see small surface defects, hydrocarbon contamination and other flaws. All bulbs have a rated life of 2,000 hours. Instant on/off/restrike eliminates lamp warm-up and reduces inspection time. The lamps produce virtually zero emission of hazardous UV-B and emit minimum visible light. The series is available in 120-, 230-, 240- and 100-volt AC versions, as well as in battery-operated versions that include a 12-volt, 7-amp per hour rechargeable battery that will operate the lamp for two full hours. A battery charger and carrying case are included.
A portable leak finder is available for locating small leaks in chambers, connections or parts. The unit has a rechargeable container for helium gas with a spray nozzle similar to an aerosol can. Helium is sprayed on the suspected leak location of a part or chamber and can then be observed on a mass spectrometer system that continuously measures the helium concentration in the part while under vacuum. A leak is immediately identified if the vacuum inside draws helium into the part or chamber. The kit includes a recharge fitting and comes in a protective, custom-made carrying case. Integral to this fitting are valves, pressure gage and pressure relief valve to allow safe recharging of the canister.
The 400 Series of Knoop/Vickers testers provides a microhardness testing solution for Knoop and Vickers testing of metals, ceramics and other non-metallic materials. The series is available with manual or automatic turrets. Having eight dial-selectable test forces ranging from 10 grams to 1,000 grams, the system can be adjusted to the correct setting for the specific specimen being tested. An optional 2,000-gram test force system is available. Equipped with optics that have a total magnification of 100X and 400X, the operator can measure the indention made during the test. The series is equipped with a 100 millimeter by 100 millimeter precision XY stage with 25-millimeter movement in each direction.
This cart-mounted Eddy Current Inspection System offers the operator the capability to inspect small lots of parts by hand on a mobile platform. Occurring in real time, inspections can be performed to verify part geometry, chemistry or hardness. The Pro Series Profiler is used to inspect parts; it is capable of profiling parts with either noncontact or contact eddy current probes and then displaying these profiles on a computer screen. The inspection system automatically calculates the part accept/reject limits from a review of 10 good parts during a “learn” process. These limits can then be adjusted by the operator, as required, to represent the characteristics of the ideal virtual part. The system’s memory is capable of storing the learned profiles from any number of parts, as well as the part profiles themselves. This information can then be downloaded from the system via USB or Ethernet ports mounted on the monitor stand.