NB/T 47013.13-2015Nondestructive testing of pressure equipments - Part 13: Pulsed eddy current testing (English PDF)

1.3 The inspection of in-use pressure equipment without cover layer can

refer to this Part.

4.2.2 Testing instrument

The testing instrument shall have the functions of pulsed eddy current signal excitation, data acquisition, data processing, signal waveform display, analysis and storage; and shall at least meet the following requirements.

a) the frequency of the excitation signal is adjustable and the falling edge is not more than 3 ms;

b) the number of data acquisition hardware shall not be less than 16 bits, and shall have synchronization function with signal excitation. For the selected probe, when the reference value is set within the valid testing range, the testing signal curve shall have a bending point;

c) it shall have a double logarithmic display function, while displaying the reference signal and testing signal; with the waveform partial amplification function;

d) the relative wall thickness of the workpiece to be tested shall be given as a percentage;

e) it shall be able to continuously store more than 100 testing points of the relative wall thickness and the corresponding testing signal waveform of the original data;

f) it can be used in -5°C ~ 40°C environment, with on-site dust, vibration and other properties.

4.2.3 Testing probe

a) it shall give the material, wall thickness, minimum diameter, cover material and thickness, protective layer material and thickness and other performance parameters applicable to test workpiece for each probe;

b) the probe shall be set with testing and overheat instructions;

c) in the case of ensuring the overall system function, sensitivity and accuracy, the extension cable can be used to connect the probe and the instrument host;

d) according to the coil placement, it can be divided into flat (vertical magnetic field) and vertical (parallel magnetic field); according to the excitation method, it can be divided into focus and non-focus.

4.2.4 Battery

The continuous power supply time of the battery shall not be less than 4h. indicates that the instrument is normal.

4.3 Testing process documentation

4.3.1 The testing process documentation includes process procedures and instructions on operation.

4.3.3 The procedures shall also specify the specific scope or requirement of the relevant factors listed in 4.3.3.1. If the relevant factors change goes beyond the provisions, it shall re-prepare or revise the process specifications.

4.3.3.1 The relevant factors involved in the process.

a) product range (workpiece shape, specifications, material, wall thickness, cover layer, etc.);

b) reference norms and standards;

c) testing equipment and apparatus, as well as calibration, verification, operation verification or inspection requirements;

d) testing process (probe configuration, testing methods, etc.);

e) pre-testing surface preparation requirements;

f) reference area;

g) analysis and interpretation of testing data. difference between the physical properties or operating conditions, the test results shall tend to have a certain deviation.

4.3.4 The preparation of operating instructions shall be based on the contents of the process and the workpiece inspection requirements. In addition to the requirements of NB/T 47013.1, its contents shall at least contain.

a) testing object. design and operating parameters, cover layer type and thickness, metal surface temperature, environmental conditions and equipment vibration, temperature fluctuations, etc.;

b) testing equipment and apparatus. probe, signal line, preamplifier, cable, instrument host, test data acquisition and analysis software and calibration specimen, non-conductive pad, metal sheet, etc.;

c) calibration specimen;

d) system verification;

e) excitation field type;

f) reference point selection and actual measurement;

g) provisions on testing initial data record;

h) determination of testing results.

4.3.5 The instruction manual shall be validated for the first time. The verification method can use comparison test block, simulated test block or the actual testing object.

4.3.2

In addition to the requirements of NB/T 47013.1, the process, procedures shall also at least contain.

a) environmental investigation requirements for testing product;

b) basic information and operation status of testing product;

c) requirements for system verification;

d) reference point selection and actual measurement requirements;

e) requirements for testing initial data record;

f) requirements for data analysis;

g) processing provisions on test results.

4.4 Safety requirements

This Part does not fully list all the safety requirements for testing. Users who use this Part are obliged to establish appropriate safety and health guidelines prior to testing. The basic safety requirements in the testing process are as follows.

a) inspection personnel shall comply with the on-site safety requirements, wear protective clothing and protective equipment as required; […]