ED-520 PORTABLE EDDY CURRENT INSTRUMENT

 

EQUIPMENT  SPECIFICATION  ES-113

 

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1.0    Description

 

1.1       The Model ED-520 is a microprocessor-based portable, self-contained, electronic instrument which offers high sensitivity, versatility, and simplicity of operation.  A continuously variable frequency control tunes an oscillator that drives a bridge circuit, one leg of which contains the test probe or coil.

 

1.2       The instrument will locate surface and near-surface discontinuities in nonmagnetic materials and surface defects in magnetic materials where permeability is relatively constant throughout the test area.  The ED-520 will sort both 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.  Also, it will measure coating thickness and relative conductivity.

 

 

2.0     Mechanical and Construction

 

2.1       Dimensions:  6” (15.24 cm) x 9” (22.86 cm) x 5” (12.7 cm) high (cover closed) 

 

2.2       Weight:  5.5 pounds  (2.48 kg)

 

2.3       Readout:  Rectangular meter, 3.5” (8.9 cm) wide.  Scale numbered from 0 to 500 in 50 divisions

 

2.4       The ED-520 is housed in a lightweight, aluminum case fitted with a removable cover and positive action latches.  The cover contains an accessory storage pocket for quick storage of probe cable(s), probe(s) and test samples.

 

 

3.0     Electrical and Performance

 

3.1       The frequency range is variable from 55 kHz to 220 kHz.

 

3.2       The instrument is operated from a single self-contained, rechargeable nickel-cadmium battery pack or from 115/220 volts AC, 50/60 Hz line power.

 

3.3       Power consumption from the battery is 4.8 volts, DC, at 160 mA and from the line 115 volts, AC, 10 watts.

 

3.4       The battery charger is a separate module with an output of 13.5 regulated volts D.C.  The cord is 72” (1.8 m) long.

 

3.5       The batteries are rated for approximately 12 hours continuous operation from the fully charged state, at 70o F, before recharging is necessary.  The recharge time required is 10 to 14 hours.  

 

 

4.0     Operation

 

4.1       The row of pushbuttons located on the bottom of the front panel selects the major operation features of the unit.  From left to right, the first group is “POWER”, “MODE” refers to the mode of operation, and “RANGE” refers to the gain setting of the unit.

 

            4.1.1    “ON” -- Pushbutton with integral LED powers the unit.  LED lights when power is applied.

 

4.1.2    “BATT” -- Momentary pushbutton which displays, on the front meter, the charge status of the battery.

 

            4.1.3    “BAL” -- Momentary pushbutton used to bring the meter pointer on scale.

 

5.1.1        “SCAN” -- Momentary pushbutton used to set lift-off.  Integral LED will light and beeper will sound as the microprocessor is performing the frequency scan.

 

            4.1.5    “FREQ” -- Momentary pushbutton enables the oscillator frequency to be displayed on the front meter.

 

            4.1.6    “LOW, MED, HI” -- Pushbuttons with integral LEDs which light when that particular gain range is selected.

 

4.2       The “SENSITIVITY” control is a single turn potentiometer used to set the sensitivity level at any point between the “RANGE” pushbutton settings.  Maximum sensitivity is obtained with this control set fully clockwise.

 

4.3       The “FREQUENCY” control is a ten-turn potentiometer with a locking counting dial.  It provides a continuously variable frequency range of 55 kHz to 220 kHz to select the proper operating frequency for lift-off compensation.

 

4.4       The “BALANCE” control is a ten-turn potentiometer with a locking counting dial.  The control adapts the probe used to the bridge circuit and is used to position the meter pointer on the scale.

           

4.5       The “ACCESSORY” connector allows accessibility to an analog/meter output and the gate/alarm output.  Connector pin designations are as follows:

 

                                    Pin 1:  Gate/Alarm Output

                                    Pin 2:  Gate/Alarm Output

                                    Pin 3:  Analog/Meter Output

                                    Pin 4:  13.5VDC with Charger plugged in

                                    Pin 5:  Ground

                                    Pin 6:  No Connection

                                    Pin 7:  No Connection

 

4.6       The “GATE” group is used when a threshold gate operation is desired.

 

4.6.1    The “GATE” switch is a four position rotary switch marked “OFF”, “DN”, “UP” and

“TONE”.  These positions determine the mode of operation on the threshold circuit.  In the “OFF” position, the threshold gate is inactive.  In the “DN” position, the threshold alarm is triggered as the meter pointer swings downscale.  In the “UP” position, the threshold alarm is triggered as the meter pointer swings upscale.  In the “TONE” position, a tone is heard only through the earphones (not included) that will vary in frequency as the needle on the meter moves.

 

4.6.2    The “POS” control is a single turn potentiometer that adjusts the point at which the threshold gate activates.  As the threshold gate is activated, the LED lights and the internal audio annunciator sounds.

 

4.7       The power connector is where the charger cord is plugged in to power the unit or charge the batteries.  Whenever the charger cord is plugged the LED will light.

 

4.8       The “PROBE” connector is a panel mounted BNC connector used to connect the eddy current probe to the unit.

 

 

5.0     Order Reference

 

5.1       The Model ED-520 Portable Eddy Current Instrument, P/N 220520, in aluminum enclosure, operating on self-contained rechargeable nickel-cadmium batteries including:

 

Probe Cable, BNC to Microdot

General Purpose Probe

Aluminum Sensitivity Standard

Power Supply/Battery Charger (must specify 110V or 220V)

Operating Manual

 

5.2     Standard Accessories

 

5.2.1    Probe Cable,  P/N 210816

 

5.2.2    General Purpose Probe,  P/N 222296

 

5.2.3    Aluminum Sensitivity Block, .008”, .020”, .040” deep slots,  P/N 225459

 

5.2.4    Battery Charger, 115/50-60/1,  P/N 520104

 

5.2.5    Battery Charger, 220/50-60/1,  P/N 520127

 

 

5.3       Addendum Accessories

 

5.3.1    General Purpose Miniprobe, 1-1/8” long x 5/16” diameter, P/N 207067

 

5.3.2    General Purpose Probe, 4” long x 3/8” diameter, P/N 062743

 

5.3.3    General Purpose Probe, 4” long x 1/8” diameter, P/N 223400

 

5.3.4    Various Wheel Bead Seat Probe Holders

 

5.3.5    Various Bolt Hole Probes (Consult Probe Catalog)

 

5.3.6    Various Hemispherical Probes (Consult Probe Catalog)

 

5.3.7    Various Sorting Coils (Consult Probe Catalog)

 

5.3.8    Strip Chart Recorder, P/N 519354      

 

5.3.9    Absolute Pencil Probe Kit,  P/N 219586

                        consists of :          1 ea. P/N 223400  Pencil Probe

                                                                1 ea. P/N 223695  Right Angle Pencil Probe

                                                                1 ea. P/N 222296S Short General Purpose Probe

                                                                1 ea. P/N 210816  Probe Cable

 

 

6.0    References

 

6.1       Instruction Manual, Form No.  25004, effective January 4, 2001

 

6.2              Price Pages EC-55

 

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