Centurion NDT ED-520ME

Centurion NDT ED-520ME

Automated Eddy Current Tester

Note: This product has been discontinued, the replacement is:

OKOndt EddyCon C Flaw Detector

Centurion NDT ED-520ME

ED-520ME Flaw Detector

Special Features:

Proven reliable microprocessor-based circuit design

  • Highly sensitive resonance-type eddy current instrument
  • Automatic push button selection of operating frequency and balance
  • Wide selection of probes and coils - interchangeable with existing equipment
  • Variable frequency range from 55 KHz to 220 KHz
  • Built-in threshold circuit includes an indicating lamp and an audible alarm
  • Extremely versatile, yet simplified operation
  • Dust-proof, weather resistant, and rugged aluminum enclosure for operation under most environmental conditions
  • Includes test block and pencil probe


The model ED-520ME eddy current instrument is an electronic device that will locate surface and near-surface discontinuities in non-magnetic materials. It also finds surface defects in magnetic materials, where permeability is relatively constant throughout the test area. In addition, the ED-520 will sort classes of materials according to such properties as hardness, alloy type, carbon content, heat treat condition, tensile strength, and grain structure (where these relate to changes in the magnetic and electrical characteristics of the test part).

With proper standards, electrical conductivity may be evaluated. This often relates to the tensile strength of many aluminum and magnesium alloys. The instrument can also be used to measure the thickness of thin, non-magnetic sheets, as well as conductive and nonconductive coatings (when used with suitable standards).

The ED-520ME is widely used in military and commercial aircraft testing, as well as process control, receiving inspection, research, and maintenance. Its compactness, ease of operation, and consistent precision make the ED-520 valuable for testing in foundries, heat treat shops, and manufacturing plants; wherever accurate data must be obtained quickly to establish fatigue or product reliability. The ED-520 features battery operation for extended field use. It is easily recharged for the AC line, using the supplied AC charger.


The push button controlled ED-520ME instrument utilizes the eddy current principle, whereby induced currents are affected by changes in test part characteristics and homogeneity. Variations in material conductivity, permeability, or physical characteristics cause impedance changes in the test probe or coil attached to the bridge circuit. Such an impedance change causes the bridge to become unbalanced, as indicated by a change on the front panel meter.

Initially, the probe (or coil) is tuned to the specific geometry, conductivity, and permeability of the test system, through adjustment of the lift-off/frequency control. This adjustment for lift-off is especially important in reducing irrelevant meter reading due to surface coatings, roughness, oxides and rocking or wobbling of the probe during testing.

With a full charge, the ED-520ME can operate on batteries continuously for at least 8 hours. Recharging takes 10-14 hours.


The ED-520ME is a portable, self contained electronic instrument offering high sensitivity, versatility and ease of operation. Either manual of automatic adjustment of frequency or balance controls allows the instrument to be set for highest sensitivity on various parts with various probes or coils. The manual controls can also be operated in conjunction with pushbuttons to permit "fine tuning" after automatic setup.

Sensitivity: Single turn cotrol for continuous adjustment of the gain between push button selectable settings
Charge: LED indicates charger is plugged in and battery is being charged.
Frequency: Continually varies adjustment of operating frequency over the range of 55 KHz to 22KHz. In the automatic set-up mode,used to fine adjust life-off/ frequency
Balance: Controls the position of the meter needle.
Gate: A rotary switch to select upscale or downscale, triggering for the threshold gate. The single turn potentimeter positions where the threshold gate triggers. The LED indicator lights up when the gate has been triggered.
Accessory: Analog outputs available for chart recorder; TTL output for relay.
Probe: BNC-type connector for a wide range of probes and coils. All previous ED-520 and ED-530 probes and coils are compatible
Volume: Determines earphone volume
Test Block: 2024 Aluminum alloy with reference slots of 0.008", 0.20" and 0.40" deep. Used to periodically check the instrument's performance.

Push Button Controls:

Battery: Depress to read battery status
ON: Power switch. Embedded LED lights when power is applied
Balance: Activates the auto balance function.
Scan: Activates the automatic lift off compensation function. Activates the auto balance function.
Frequency: Depress the display operating frequency
Range: Selects between the three sensitivity levels for the unit


Case Dimensions: (cover closed): 6" deep x 9" wide x 5" high (15.2cm x 22.9cm x 12.7cm)
Weight: 5.5 lbs. (2.48 kg)
Power: Rechargeable Ni-Cad Battery. Line operation must be specified to operate 115 or 230 V
Enclosure: Case is made of durable aluminum and the cover contains an accessory packet
Frequency Range: Variable from 55 KHz to 220KHz
Readout: Rectangular meter, 3.5" wide.Scale numbered from 0 - 500 in 50 divisions
Environment: oº to 120° at 85% RH

ED-520ME Microprocessor Based Eddy Current Instrument includes: Aluminum 3 slot Test Block, General Purpose Probe, Probe Cable, BNC to Microdot, Power Supply/ Charger, 115 VAC or Power Supply/ Charger and 220 VAC.

Product Literature

Description Part # Saved Price Select Option Add to
Centurion NDT ED-520ME Eddy Current Tester w/ Probe EC-CNDT-220520 Request Pricing