CIRCOGRAPH® Sensor systemsRotating Head Ro 35 P 6.461.01Rotating Head Ro 35 L 6.461.21

�The optimum rotating headfor eddy current testing ofmetallic semi-finished ma-terials in the diameterrange:Ro 35 P 2 to 35 mmRo 35 L 5 to 35 mm

�High throughput at testingspeeds of up to 3 m/s

�Minimum retooling timefor dimension changes bylateral access

�Very compact design, over-all length of only 345 mm

�Sturdy, breakdown proofdesign

�Ro 35 P with 2 or 4 testheads performed as pin,particularly suitable forlargely high flaw resolutiontogether with high preci-sion material guidance

�Ro 35 L mit two or four testheads performed as le-vers, particularly suitablefor integration in produc-tion machines, e.g. draw-ing lines

�Roller guide on option,overall length + 63.5 mm

Rotating Head Ro 35 L / Ro 35 Pwith roller guide

® Registered trade-marke

Features

� Highly sensitive, contactless testing for mainlylongitudinally oriented surface flaws

� Electronic clearance compensation in the en-tire diameter range from 2 (5) to 35 mm withCIRCOGRAPH DS

� With CIRCOGRAPH CP without clearancecompensation

� Longitudinally oriented surface flaws can be de-tected as from a flaw depth of around 30 µm

� High throughput without untested gaps:testing speed of 3 m/s at 9,000 rpm when usingfour test heads with a track width of 5mm each

� Fast and easy dimension change, snap-lock noz-zles, self-clamping adjustment of test heads

� Improved test head protection thanks to a re-duced distance between the entry and exit noz-zles

� Compact design with a length of only 345 mmwithout the attached roller guide when materialguidance is guaranteed by installation in the pro-duction machine

� Optional compact roller guides extend the overalllength by only 63.5 mm

� With small testing diameters the use of the op-tional roller guide supports material centering

� Compressed air terminal for blowing the testheads free

Application

� Non-destructive eddy current testing of metallicround materials (wires, bars and tubes) forsu rface f laws in con junc t ion w i th theCIRCOGRAPH® electronic testing and evalua-tion system and a suitable transport mechanism

� Test material diameter range from 2 to 35 mmresp. 5 to 35 mm

� Requirements for test material and ambient con-ditions:

� surfaces as devoid as possible of scale andprotruding burr

� Straightness£ 2 mm/m

� Max. material temperature + 80 °C; blow-freeunit connection recommendedt

� The rotating heads Ro 35 PL can be connected toCIRCOGRAPH DS electronic unit with two or fourchannels (see leaflet CIRCOGRAPH DS 6.430)and to CIRCOGRAPH CP 1-channel (withoutelectronic clearance compensation, see leafletCIRCOGRAPH CP 6.412)

� Test heads with track width [BS]Ro 35 P 1,5 - 2,5 - 5 mmRo 35 L 2,5 - 5 mm

� 2 variants of the motor control are offered for op-eration with the Ro 35 P/L:

� Motor control MOC EFixed speed of 4,500 rpm50 Hz mains connection

� Motor control MOC SFixed speed of 9,000 rpmswitchable to half rotational speed

� Manually brake as standard

� Electrically brake as option with MOC SB

2 6.461 - 00/49

Operating principle

The transmitter system Ro 35 P/L operates in ac-cordance with the eddy current principle in confor-mity with DIN 54 140. Rotary probes rotate at ashort distance and at a high speed around the lon-gitudinally moved test object and helically scan itssurface without physical contact.

The rotary probes scan discrete points, merely reg-istering a small portion of the overall surface at anygiven moment.

In relation to the relatively small registered materialsurface, every material flaw that the probe passesover represents a “large fault“.

Therefore, the rotary probe detects extremelysmall material flaws with a high resolution.

Each time the rotary probe passes over, extendedmaterial flaws generate a signal so as to ensurethat the full length of the flaw is indicated.

If a suitable material transport speed (“test speed“)is chosen, the probe’s test tracks follow without un-tested gaps so as to ensure complete scanning ofthe material’s surface.

The maximum test speed is the result of the revolu-tion speed, the number of probes and the probetrack width.

With two probes offset by 180° resp four probes off-set by 90°, the tracks follow in succession withoutgaps or overlaps when the test object is trans-ported forwards by two resp. four track width in ev-ery revolution.

The signals picked up by the probes are trans-ferred from the transmitter system to the electronictest unit for evaluation.

The field current for powering the probes and theprobe output signals are transmitted without physi-cal contact by rotary transformers.

The electronic unit consists of a process-controlledelectronic testing and evaluation unit featuring in-teractive operation and convenient display anddocumentation possibilities.

.

6.461 - 00/49 3

SondenwirkbereichEffective probe area

SondenrotationProbe rotation

Riß Crack

RotiersondeRotating probe

Fig. 1 Rotating probe on material flaw

Rotiersonde

Rotating probe

Gesamtfehlersignal

Overall flaw signal

Abtastspuren Scanning tracks

Fig. 2 Scanning track and flaw signals

Abtastspuren Scanning tracks

3

41 2

4

233

4

2

1

Fig. 3 Scanning tracks, four probes offset by 90°

Structure

Besides the rotating head, which scans the test ma-terial and which generates the eddy current signal, aCIRCOGRAPH electronic test unit, a motor contolunit and two connecting cables are needed for acomplete testing system.

The rotating head Ro 35 P/L 6.461 consists of the fol-lowing obligatory components:� Rotating head Ro 35 P/L� 2 resp 4 test heads

(adjustable according to a scale)� Protective nozzles� Motor control� Test and control cables, motor cable

The following are optionally available to improveadaption to the conditions of the testing task:

� 2 roller guides� Sliding table� Tilting table (without roller guide only)� Special guide unit� Main voltage adaption

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Bild 4 Structure of a test unit

Sensorsystem Ro 35 P/Lwithout roller guide

CIRCOGRAPH DS 6.430

Motor control MOC S (SB)

CIRCOGRAPH CP 6.412Motor control MOC E

Sensorsystem Ro 35 P/Lwithout roller guide

Rotating head Ro 35 P/L

The rotating head consists of the following components:

� Bearing caseOne chamber envelops the test zone.

� Three-phase driveIndestructible drive featuring a standardsquirrel-cage motor connected to anexternal motor control.

� Hollow shaft with contactless rotary transformer

� Rotating head electronicsThe electronic system of the rotating head ampli-fies the probe signals and the field current and isfitted in a sturdy box on the side of the bearingcase for easy servicing.The cables to the test electronics are connectedby means of MIL connectors.

� Start-up protection when the bearing case is open

� Handbrake toconsiderably reduce the run-out time

Protective nozzles

The protective nozzles perform a dual function:

� Centring the test material in the test zone to a di-mension that can be balanced out by the clear-ance compensation.

� Breakdown protection for the test heads,particularly during fit-in and exit of the test mate-rial provided the straightness and end conditionsare met.

6.461 - 00/49 5

Fig. 5 Rotating head Ro 35 P/L Bearing case open

Fig. 6 Protective nozzles with nozzle holders, assembly tool positioned

Rotating head electronics

Start-up protection

Bearing case

Hollow shaft

Three-phase drive

�It is imperative to use diameter-adaptedprotective nozzles. Nozzles with thesame nominal dimensions must alwaysbe used. For breakdown and safety rea-sons, operation without protective noz-zles is forbidden.

Protective nozzles are available in the following nom-inal diameters (NM = nominal diameter):

2,0 to 8,0 mm: material diameter + 0,1mm> 8,0 to 15 mm: material diameter + 0,5 mm> 15 to 35 mm: material diameter + 1,0 mmProtective nozzles can be ordered or can be pro-duced by the customer according to a drawing.

Please enquire about a special guide unit, particu-larly for use with highly sensitive materials such asCu tubes, polished surfaces etc.Generally,no additional roller guide is recommendedwhen using special guide units.

6 6.461 - 00/49

Fig. 7 Protective nozzles Ro 35 L, nozzle holder with replaceable nozzles, schematic diagram NM 5 to 36 mm

Fig. 8 Protective nozzles Ro 35 P, nozzle holder with replaceable nozzles, schematic diagram NM 2 to 36 mm

Motor controls

Motor control MOC E

Fixed speed of 4,500 rpm,50 Hz mains connection

Motor control MOC S

Speed of up to 9,000 rpmswitchable to half rotational speed

Roller guide

Roller guides are recommended whenever the mate-rial transport drivers cannot be set up directly beforeand after the transmitter system.

The roller guides offer two advantages:

� In the set up mode, a calibration piece featuringcomparison flaws can be comfortably held in acentral position outside of the test line and theelectronic test unit can be adjusted easily be-cause the rotary probes periodically scan the testflaw and the signal is displayed practically stati-cally.

� The roller guides improve centricity, particu-larly in the lower dimension range, and reducevibrations.

The roller guides are fitted on the rotating head on theentry and exit sides.Diameter adjustment by hand wheel.

The complete diameter range of the Ro 35 P/L iscovered by two roller sets:

� Ø 4.5 - 35 mm Standard roller set

� Ø 2 - 8 mm with additional roller set

6.461 - 00/49 7

250

150

375

600

300

1400

Fig. 9 MOC E MOC S

Fig. 10 Roller guide

Tables

If guide units are positioned particularly close to-gether, a sliding or tilting table facilitates replacementof the nozzles and maintenance work.

Tilting and sliding tables are conceived as special ac-cessories for test lines.

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Fig. 11 Sliding table which moves transverse to the test line

Fig. 12 Tilting table featuring a swivel axis parallel to the test object axis

Technical data

Ro 35 P/L

Diameter range testing material 2 (5) to 35 mm, continuously adjustable

Revolution speed 4.500 rpm with motor control MOC E

or 9.000 rpm with motor control MOC S/SB

Type of test without physical contact

Test heads

with pin type probes for Ro 35 P

with lever type probes for Ro 35 L

adjustable according to a scale

two, offset by 180° , with one probe each, or

four, offset by 90° , with one probe each

Probe track width: Ro 35 P

Ro 35 L

5 mm, 2,5 mm, 1,5 mm

5 mm, 2,5 mm

Test speed for gapless

(5 mm track width)

1.5 m/s at a speed of 4,500 rpm,

3.0 m/s at a speed of 9,000 rpm

Dimensions see dimension drawing

Mass approximately 70 kg

Power supply 3 x 400 V three-phase for the drive,

if the supply voltage differs,

adaption via an isolating transformer

Drive Three-phase motor, no = 1425/2850 rpm, P = 1.4/1.8 kW

Useful bearing life at max. speed

(depending on ambient conditions)

Grease lubrication 4.500 rpm

9.000 rpm

Typical operating hours

app. 7.000 h

app. 5.000 h

Roller guide (option)

Standard

Additional

Mass

Dimensions

Ø 4.5 to 35 mmØ 2 to 8 mm

approximately 3.8 kgSee dimension drawing

6.461 -03/2002 9

10 6.461 - 00/49

3031

3233

3435

3637

2928

3029

2830

3132

3334

3536

3729

2834

3536

37

129

63,5 63,5

140

190345

35713

5

ca.5

60408,5343

2514

Fig. 13 Dimension drawing 1

6.461 - 00/49 11

95

18

11

250

279,5220

Fig. 14 Dimension drawing 2

OU

TS

TANDING!

FÖRSTER

DQS-REG.NO 1159-01

the first German manufacturer

of eddy current equipment with

certification

ISO 9001

Should you have any special problems please contact:

INSTITUT DR. FÖRSTERPrüfgerätebau GmbH & Co. KGPostfach 15 64D-72705 ReutlingenIn Laisen 70D-72766 ReutlingenPhone +49 (0) 7121-140-270Fax +49 (0) 7121-140-459e-mail ts@foerstergroup.dewww.foerstergroup.deor one of our agencies abroad

Information and illustration maybe subject to change

Order-No. 1638564

Edition 03/2002Author Sy