TB/T 2340-2012Ultrasonic testing detector for rail (English PDF)

4.1 General rules

4.1.1 The detector shall be able to apply to the automatic defect detecting operation for in-service rail with 43 kg/m-75 kg/m.

4.1.4 Each channel of the detector shall be equipped with sound alarm device; the sound in each channel shall be easy to distinguish.

4.1.5 The detector shall be equipped with an attenuator.

4.1.6 The detector shall be powered by storage battery; the capacity of the battery shall be able to meet the requirement that the detector continuously operates for 8 hours.

4.1.10 The detector shall be no damage on its surface; there is no damage on the devices and components. The performance of each switch shall be stable; the display of indicator light, oscilloscope tube or display screen and others shall be normal.

4.1.11 The components of detector of the same model shall be exchangeable.

4.1.12 The digital detectors shall have functions such as measuring speed, data replaying, over-speed alarming, and delivering data according to specified data format.

4.2 Probe

4.2.1 General rules for probes

4.2.1.1 The surface of the probe shall be no damage. the probe wiring shall be flexible; the plug-in of connector shall be reliable; the shield shall be good.

4.2.1.2 The connectors of the probe shall meet the requirements of superior product or first grade class product in standard SJ/T 9562.2-1993.

4.2.2 Probe performance

4.2.2.1 Physical properties

For flat probes, the flatness tolerance on the probe coupling surface shall not be more than 0.05 mm.

4.2.2.2 Echo frequency

Transverse-wave probes. 2 MHz~2.5 MHz; longitudinal wave transducers. 3.5 MHz~5

MHz or 2 MHz~2.5 MHz.

4.2.2.7 Attenuation value of protection boots (film)

The attenuation value of protection boots (film) shall be less than or equal to 8 dB.

4.2.2.8 Resolution

The resolution R of 0° probe shall be >=18 dB; the resolution R of offset-angle probe shall be >=14 dB.

4.2.2.9 Sensitivity margin

The high and low sensitivity of probes is expressed by the sensitivity margin after the probe has been combined with instruments; the specified value of sensitivity margin S is.

4.3.3 Dynamic range

Minimum limitation. It shall not be less than 16 dB. Maximum limitation. 2 dB~6 dB.

4.3.4 Amplifier frequency response

The central frequency obtained by f0 = (fu x fi)1/2 shall be within ±10% of nominal value.

The amplifier bandwidth deltaf (3 dB lower-point) obtained by deltaf = fu - fi shall be within ±10% of nominal value of bandwidth, and shall not be less than 40% of the nominal central frequency of the probe.

4.3.9 The effects of operation voltage on the wave height of detector echo and the sensitivity of detection (alarm)

Within the rated operation voltage, the position of the detector gate and alarm electrical level shall have no significant change; the change deltaNd of echo amplitude and the detection (alarm) sensitivity change deltaSd shall not be larger than 1dB respectively.

4.3.10 Digital detector

4.4 Combination property

4.4.1 Sensitivity margin

0° probes. When detecting the 110mm bottom-surface of the WGT-3 test block, and when the wave height reaches 80%, the sensitivity margin shall not be less than 36 dB.

35° probes and 70° probes. When detecting Phi3mm cross-hole with 65 mm depth on the

WGT-3 test block (see Annex A), and when the wave height reaches 80%, the sensitivity margin shall not be less than 40 dB.

4.5 Electromagnetic compatibility

The detector shall have relative strong anti-interference ability and can work normally nearby the electrified lines and stations. The electromagnetic compatibility of the detector shall comply with provisions of Chapter 6 (Performance decision A) in GB/T

18268.1-2010.

4.7 Temperature stability

When the temperature changes by 10°C, the amplitude and range change of reference echo cannot exceed ± 5% and ± 1% respectively.

4.8 Vibration performance

The detector shall be able to operate normally after the test in 5.8.

4.9 Drop performance

The detector shall be able to operate normally after the test in 5.9.

4.10 Sealing performance

The detector shall be able to operate normally after the test in 5.10.

4.11 Safety performance

The insulation resistance between the traveling wheel and frame of the detector shall not be less than 1 Mohm; other parts of the detector shall meet insulation requirements.

5.1 Inspection conditions

5.1.1 Environment condition. In addition to operation ambient temperature test, other tests

can be carried out when the temperature is 10°C-30°C; the relative humidity is 50%-70%;

the operation voltage does not exceed the rated operation voltage of the detector for rail;

the external magnetic interference and direct sunlight shall be avoided with good ventilation.

5.1.5 The test of combination property shall use coupled probes provided by the manufacturer.

5.1.6 Coupling agent. Clean machinery oil or clean water.

5.2 Probes

5.2.1 Physical properties

Visually inspect whether there are proper identification and assembly on the outer surface of the probe and physical damage that may affect the current or future reliability. Measure the flatness of the probe coupling surface with knife-edge ruler and feeler gauge.

5.2.4 Refraction angle error

Inspect it according to provisions of 3.2.7 in JB/T 10062-1999.5.2.5.1.

5.2.5 Acoustic-axis offset angle

5.2.6 Relative deviation of combined probe

Take the longitudinal center-line of probe housing as a base-line; use ruler to measure the vertical distance alpha1 and alpha2 from the two probe centers to the base-line.

5.2.7 Attenuation value of protective boot (film)

Detect R100 mm arc surface of CSK-I A test block by using a 70° probe with protective boot (film); move the probe back-and-forth; and keep the probe parallel to the side of test block.

5.2.8 Resolution

Resolution can be measured with universal flaw-detector conforming to JB/T 10061-1999 standard; the instrument inhibition is set to “zero” or “off” position when testing; it can add the matching coil if necessary.

5.3 Instrument

5.3.1 Pulse repetition frequency

Inspection method is performed in accordance with the provision 4.12 of JB/T

10061-1999.

5.3.6 Vertical linearity error

Measurement channel inhibition of flaw-detector is set to “0” or minimum; the attenuator has at least 20 dB of attenuation margin; find a reflected wave with the sound path equivalent to 100 mm ~ 200 mm longitudinal wave on WGT-3 test block; take it as the reference wave; adjust the gain and make the amplitude of reference wave up to 100% (the base-line of relative measurement channel).

5.4.4 Flaw-detection capability

Rail flaw-detector is in an assembled state; it is pushed-travelled at normal flaw-detection speed; under the condition at a fixed flaw-detection sensitivity and no false alarm, other artificial defects on GTS-60 test block, other than 15° lower crack, shall be found one by one. In order to facilitate to distinguish the alarm sound, it can test different channels separately; it may also lengthen the test block, or process the defects of GTS-60 test block onto multiple test blocks for testing.

7.1 Mark

Nameplate of flaw-detector shall identify the type of flaw-detector (high temperature, low temperature, ordinary), manufacturer’s name, manufacturing time and serial numbers.

7.2 Packaging

Product packaging shall be dustproof, waterproof, anti-vibration and pressure resistant;

the instrument shall be isolated from the car and be packaged separately; the packaging mark shall be obvious.

7.5 Accompanying documents

Annex A (Informative Annex)

WGT-3 test block

A.1 Technical conditions

A.1.1 Chemical composition, grain size and internal defect inspection of test block

material shall refer to JB/T 10063-1999.

A.1.2 Limit deviation of unspecified tolerance size is in accordance with IT 14.

A.1.3 Test block is produced by professional factory and shall conduct the united acceptance.

Annex B (Informative Annex)

GTS-60C lengthened test block

Material and size of GTS-60C lengthened test block base shall comply with the provisions of TB/T 2344 corresponding technical requirements; all slot widths are 0.2 mm~0.3 mm.

Other size requirements are shown in Figure B.1.

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