MAC eddy current inspection systems incorporate computer based test instruments and test coils. The test coils interact with the material under test and provide data which is processed and analyzed by the instrument. MAC uses two general types of eddy current test coil technologies: Encircling and Sector Coils, and Spinning or Rotary Probe Coils.

• Eddy Current Instruments
• Eddy Current Test Sensors

E-Rotary 750 Rotary

In rotary probe technology, the product under test moves longitudinally through the rotating test probes resulting in a helical search pattern. As the probe passes over a defect, variations in the induced eddy current pattern are detected. The minimum flaw length which can be consistently detected is a function of the rotary speed of the probe and the throughput speed of the material. Similar results can be obtained by holding the test probe stationary and rotating the material past the probe. For rotary testing of hot material, the Rotomac® BQ hot tester is available. Current MAC rotaries feature continuously variable high speed rotaries (1800 - 6000 RPM), and multi-probe headplates to detect shorter defects without sacrificing throughput speed. Similar results can be obtained by holding the test probe stationary and rotating the material past the probe. Rotary testing is the method of choice for detecting seam type surface defects in non-magnetic and magnetic grades of wire and bar. MAC has rotary mechanics for up to 7-1/2 inch (191mm) diameter material. The MultiMac eddy current instrumentation operates with MAC rotaries where long, continuous defects may not be adequately detected by encircling test coils.

Typical applications for rotary test sensors are:

• Detect seam type surface defects in cold drawn wire or cut length bar stock
• Inspect in line with continuous wire operations such as wire drawing, parts forming, re-spooling, or straight and cut
• Inspect cut lengths, usually off-line
• Test parts, such as small shafts and bearings for longitudinal surface defects

PDF File:  EC ROTARIES 2010.pdf
For Use With:  Bars and Rods, Wire

The versatile new MultiMac® lets you configure your eddy current test application the way you want - all with just one tester. MultiMac test channels can be individually configured for use with encircling or sector test coils as well as rotating test probes - eliminating the need to have several instruments.

The MultiMac is also available in other cabinet configurations that do not include the heavy duty cabinet and built-in monitor. These models include output connectors for an external monitor, and can be housed in an environmental cabinet with air conditioning where needed.

Defect detection in non-magnetic and magnetic bar, wire, or tube where multiple test channels and both encircling and rotary probe technology is desirable.

PDF File:  MULTIMAC 2010.pdf
For Use With:  Bars and Rods, Tubing, Wire

The MultiMac SM is a high speed, computer with Windows® Operating System and MAC's latest proprietary software. The instrument is packaged in a compact cabinet that includes a built-in touch screen monitor and may also be operated with a keyboard or mouse. The output connectors are included for an optional external monitor.

 With these features, MultiMac SM can operate on a wide variety of non-magnetic products, or use Direct Current saturation systems to inspect magnetic material.The system has a broad test frequency selection from 1KHz to 5MHz.  Test speeds can range from one foot per minute up to several thousand. Installation can be in-line or at a separate test station.

 MultiMac SM has up to 4 test channels that can operate at the same or different frequencies for special applications.  The main test display provides all the information needed to set up and operate MultiMac SM. Polar and linear signal traces can be simultaneously displayed, along with all test parameters.  User configurable reports containing customer and product information in addition to defect location, time, amplitude and phase can be stored locally or on a network server.

 To detect short weld line defects, and long, continuous surface flaws such as laps and seams in magnetic and non-magnetic tube and bar.

PDF File:  MULTIMAC SM 2010.pdf
For Use With:  Bars and Rods, Tubing

Designed for continuous production testing applications, where simple set-up without critical operator adjustment is desired.

Windows based industrial quality eddy current tester with complete networking capabilities. Software controls for all functions including phasing, filtering, sensitivity and frequency. Separate full color polar and linear monitor display of real time, true wave form signals for review on site or in remote location. Inspects magnetic and non-magnetic tube, wire and bar stock at speeds up to 4,000 fpm.

Defect or weld detection in non-magnetic tubing or wire, and continuity checking on single and multi-conductor insulated wire and cable.

PDF File:  MINMAC40-2010.pdf
For Use With:  Bars and Rods, Tubing, Wire

The convenient MAC® 400 with up to four independent channels can be connected to segmented encircling or sector test coils.

Windows® based, this CE tester displays results and settings on large on-screen windows. Each channel is either independent or synchronized, with the independent setup being used for multi probe scanning applications where multiple probes can inspect the material surface. The synchronized setting can be used for multiple sensors with a common feed system such as in segmented encircling coil applications.

The MAC 400 can be monitored and operated through a network for quick and easy follow up. Settings can be conveniently entered by keyboard, mouse, or by point and drag features on an optional touch screen monitor.

Non destructive testing for defects, including weldline defects, laps, or open welds in magnetic and nonmagnetic bar, wire or tubing, on or off line, with straighteners and other production equipment.

PDF File:  MAC 400.pdf
For Use With:  Bars and Rods, Tubing

The Varimac V, latest in MAC's line of eddy current comparators gives you fast, convenient sorting of metal parts such as fasteners, bearings, and other cold formed pieces. Its high speed continuous operation and reliability in production environments make 100% non- destructive inspection economically feasible. It is also used for checking alloy and hardness in bar or wire.

Detect variations in alloy, hardness, some dimensions and certain types of cracks in metal bar, tube or parts. Also used for high speed sorting of parts such as fasteners and bearings. Used with MAC's Parts Gates, parts can be sorted and counted at speeds up to six parts per second into three separate groups.

PDF File:  VAR5.pdf
For Use With:  Bars and Rods, Metal Parts, Tubing

A single frequency Windows® computer based nondestructive test instrument that uses low frequency electromagnetic techniques to inspect magnetic materials for variations in physical characteristics such as alloy, heat treatment and case depth. Highly selective gating circuit permits it to discriminate between changes in the signal’s phase, amplitude or harmonic distortion from the fundamental frequency to its 13th order harmonic. The instrument also features a unique display (vector or lissajou) that provides simultaneous display of the standard, acceptable piece and the test piece wave forms for easy comparison. Setup and monitor on site or through a computer network.

Checking case depth, core hardness, alloy and structure in ferromagnetic tube or bar at production line speeds on line or off line. Three way sorting of magnetic parts automatically, when used with MAC’s automated Parts Gates.

PDF File:  PCVI_2010.pdf
For Use With:  Bars and Rods, Metal Parts, Tubing, Wire

Standard Parts Test System
MAC standard NDT parts testers usually utilize the Varimac V eddy current comparator with an automated parts sorting gate to separate parts into three categories - above specification, below specification and acceptable. The sort speed of the Varimac V instrument is only limited by the parts handling and sorting mechanism. Used in conjunction with MAC's Model 570 gate system, for example, the Varimac provides reliable, 3 way sorting at speeds up to 6 parts per second, based on differences in alloy, hardness, case depth, grain size, processing variations, plating thickness, some dimensions and orientation.

Customized Parts Testers
Highly sophisticated customized parts testers using several test technologies and appropriate automated handling equipment have been developed and produced for inspecting shell bodies, grenades, bearing races, and automotive parts, among others.

Inspect and sort for hardness, alloy, or other physical characteristics in metal parts.

PDF File:  VAR51.pdf
For Use With:  Metal Parts

Used with an internal test probe, the MAC 141 provides a high performance, low cost eddy current test for the inspection of non magnetic heat exchanger tubing in condensers, evaporators and similar applications.

Optional, user friendly tube mapping software produces a permanent tube map of the results, either during or after the job. Data can be shown in tubular, chart or tube map mode and the tube map can be customized for the specific heat exchanger configuration.

On site non destructive inspection of specialty stainless alloy and titanium tubing in condensers, evaporators and similar portions of air conditioner units.

PDF File:  PROMAC 141_2010.pdf
For Use With:  Tubing

The type 2WR Wire Rope Tester is designed to inspect magnetic grades of wire rope up to 1" (2.54cm) in diameter. It is capable of detecting a single broken wire in most forms of wire rope, preformed or otherwise, whether the broken stand is on the surface of the bundle or buried. The system is composed of a compact, ruggedly built solid state flux leakage control unit, plus energizing and detector units. The energizing and detector units create a strong magnetic field which causes lines of magnetic flux to pass through a small length of the wire rope under test. Any broken wire causes a change in the flux field which is sensed by the detector. The detector is a unique split coil, designed to allow the coil to be placed on a rope either in the field or on a production line without having to thread an end through an encircling coil.

Magnetic wire rope testing for broken stands either in the field, or in the factory.

For Use With:  Wire

The Rotomac® BQ rotary eddy current test system is successfully detecting long, continuous defects in hot wire during production in a key Scandanavian steel hot mill. Used in conjunction with an encircling coil eddy current test, the system offers reliable detection of both short and long defects in hot wire.
 

The rotary eddy current test utilizes test probes which spin around the wire as it passes through. The helix test pattern that results detects long defects that are present, at each pass. By using rotary probes to detect long defects in combination with an encircling coil to detect short defects, the Rotomac BQ detects the widest range of flaws, even at the high through put speeds typical of wire production.
 

The electronics analyze and present an integrated screen of the data from both the rotary and encircling tests on a monitor. Results are color coded for severity. Low level defects can be counted per unit of length and defects detected by the rotary and encircling tests can be recorded, integrated, stored and networked.
 

Systems for wire ranging up to 37mm diameter are available. Customers who already have an encircling coil system in place can "upgrade" to a Rotomac® BQ complete system with the addition of the rotary tester. For new installations, the customer can install the complete system or begin with either an encircling or rotating test, depending on the type of defects that are most prevalent, and then add the other test at a later date.
 

Testing wire in hot rolling mills

PDF File:  ROTOMAC BQ 2010.pdf
For Use With:  Bars and Rods, Wire

Demagnetizers are used in metal manufacturing plants to eliminate residual magnetism in the test material after the eddy current test is completed, or for similar applications where high speed reduction of residual magnetism is required. MAC Demagnetizers can handle bar, tube or wire material ranging up to 8.5" (215 mm) diameter.

Models include:

Low Power for up to 1.75" (44 mm) Diameter Light Material such as thin wall tube and small parts

• Model 200 Demagnetizer - AC power only - Ambient Air Cooled

  1 KVA Power for 1.75", 4.75" or 5.75" (44, 114, 146 mm) Diameter Material

• Models 470/471 - Ambient Air Cooled

  Medium Duty 4 KVA Power for 4.5" (114 mm) Diameter Material:

• Model 475 - Water or Air Cooled (Air cooled coils can be used on some thin walled tubing)

  Heavy Duty 25 KVA Power for 3.75", 4.75" or 5.75" (95, 114, 146 mm) diameter material - Requires continuous supply of water for cooling. Contact MAC for specific water and power requirements.

• Model 400

  Extra Heavy Duty 75 KVA for 7.5" or 8.5" (190, 215 mm) diameter material

• Model 750 Demagnetizer. Requires continuous supply of water for cooling. Contact MAC for specific water and power requirements.

  MAC's experienced Field Engineers can recommend the most appropriate demagnetizing equipment for your applications.

Used to eliminate residual magnetism in the test material after the eddy current test is completed, or for similar applications where high speed reduction of residual magnetism is required

PDF File:  Demagnetizer 2010.pdf
For Use With:  Bars and Rods, Metal Parts, Tubing, Wire