GB/T 26837-2011Non-destructive testing instruments - Stationary type and movable type industrial X-ray radiographic equipment (English PDF)

4.2 Performance

4.2.4 The X-ray machine shall be equipped with the exposure cumulative timer, to record the cumulative exposure time of the X-ray tube.

4.2.5 The X-ray machine shall have a timer that controls the duration of exposure. The maximum error of the timing shall not be greater than ±2% of the indicated value of the measured point.

4.2.6 The maximum allowable error of the X-ray machine tube-voltage shall not exceed ± 5% of the measured value (power frequency, oil-insulated machine).

4.2.7 The X-ray machine shall be provided with a tube-voltage regulated-device, the starting tube-voltage shall not be greater than 20% of the rated tube-voltage.

4.2.8 The X-ray machine shall be equipped with an overvoltage protection device. When the tube-voltage exceeds the rated tube-voltage of 5 kV ~ 10 kV, the high-voltage shall be disconnected.

4.2.9 The X-ray machine shall be provided with a temperature protection device.

When the temperature inside the generator reaches 60 °C ± 5 °C, the high-voltage shall be disconnected.

4.2.10 The X-ray machine shall be provided with an under-millimeter protection device. When the tube-current is less than 0.5 mA, the high-voltage shall be disconnected.

4.2.11 The X-ray machine shall be equipped with an overcurrent protection device. When the tube-current is greater than the rated tube-current of 1 mA, the high-voltage shall be disconnected.

4.3 Stability

4.3.1 The X-ray machine shall work continuously for 10 times in accordance with the specified working procedures. There shall be no abnormal phenomena during the test, the temporary load rate shall conform to the nominal data. Each continuous working time shall be no less than 10 minutes.

4.3.2 The X-ray machine shall be equipped with a voltage stabilized-circuit. The tube-voltage fluctuation shall be within ±2%; the tube-current fluctuation shall be within ±0.5 mA. to ground shall be not less than 5 M ohm.

4.4 Radiation protection and safety

4.4.6 The primary insulation resistance of X-ray machine's filament transformer to ground is tested by the 1000 V, 50 Hz AC, there shall be no abnormality after withstanding voltage for 2 min.

4.4.7 The X-ray machine shall have a grounding protection device; the grounding resistance shall be less than 0.5 ohm.

4.4.8 The impurities of the X-ray machine's controller and high-voltage generator (power frequency, oil-insulated) shall not be more than 100 mg.

4.4.9 The cable connector and plug connection of the X-ray machine are convenient to disassemble. The number of thread is not less than 3 and has a protective cover.

4.4.10 The X-ray machine's generator assembly shall be capable of locking at any desired location and capable of emitting X-rays in the desired direction. The generator support shall be able to support the X-ray generator, it has 3 degrees of freedom, be sensitive and has brakes.

4.4.11 The X-ray machine generator and cooling circuit shall be free of leakage.

4.5 Appearance requirements

4.5.1 The surface coating shall be firm and free from falling off.

4.5.2 Surface finish and finished surface shall be free from bumps, air bubbles and scratches.

4.5.3 Unrefined rust-sensitive surfaces shall be protected against rust.

4.5.4 The surface color is clear; the color of the controller and generator of the same model shall be the same.

5.1 Test conditions

The test conditions shall comply with the provisions of 4.1.

5.2 Main instruments and appliances for testing

5.2.1 AC voltmeter and ammeter not lower than grade 1.0

5.2.2 Ball gap discharger or electrostatic voltmeter, the maximum measurement error is ± 3%.

5.2.3 The 1.0 grade 500 V insulation resistance meter.

5.2.4 X-ray dosimeter, with a total uncertainty of ±10%

5.2.5 Densitometer or micrometer with a measurement error of not less than ± 0.04%.

5.2.6 Verification test block (as specified in Appendix A) and the line type image quality meter.

5.2.7 Lead intensifying screen (0.03 mm), industrial X-ray film

5.2.8 Intensive light adjustable reading light

5.2.9 Stopwatch and thermometer

5.2.10 Continuous impact test bench, high and low temperature box, damp heat box.

5.2.11 Dielectric strength tester with a capacity of 150% above of the power of the X-ray machine under test.

5.2.12 Barometer and air pressure test device

5.2.13 Balance which has an accuracy of milligram grade.

5.2.14 X-ray dose rate meter

5.2.15 Halogen leak detector

5.2.16 Grounding resistance measuring instrument […]

5.3 Penetration determination

5.3.1 Test equipment

Standard test blocks which comply with the provisions of Appendix A, industrial films which comply with the industrial film of ISO sensitivity 320 as listed in Table 1 of GB/T 9582-2008, viewing lights which comply with the laboratory requirements, densitometer which complies with the requirements of 4.2 of JB/T 6220-2004.

The schematic diagram of this test is as shown in Figure 2.

5.8 Determination of X-ray machine's tube-voltage's regulated-

device Use the tube-voltage regulator on the controller to observe the indication value.

Place the kV knob at 20% of the rated tube-voltage, start the X-ray machine.

5.9 Determination of overcurrent protection

Adjust the tube-voltage to 50% of the rated value, the tube-current is the rated value; after at least 1 min of the simulated exposure, make the tube-current exceed the rated value. At this time, it is necessary to make adjustment carefully and slowly, observe whether the tube-current's indication value at the instantaneous of high-voltage disconnection is within the specified setting range, make a record. If the high-voltage has been automatically cut off when the tube-current does not reach the set value, or the high-voltage cannot be automatically cut off 5 s after the current exceeds the setting value range, stop increasing the tube-current continuously. In the event that the tube-current's indication value is not within the specified setting range at the instantaneous that the high-voltage is cut off, it shall consider that the overcurrent protection device is not well adjusted or failed.

5.10 Determination of overvoltage protection

Adjust the regulator to make the supply voltage which is indicated by the voltmeter to be rated value. Adjust the tube-voltage to the rated value, after maintaining for 1 min, make the tube-voltage exceed the rated value. At this time, it is necessary to make adjustment carefully and slowly, observe whether the tube-voltage's indication value at the instantaneous of high-voltage disconnection is within the specified setting range, make a record. If the high-voltage has been automatically cut off when the tube-voltage does not reach the set value, or the high-voltage cannot be automatically cut off 5 s after the tube-voltage exceeds the setting value range, stop increasing the tube-voltage continuously. In the event that the tube-voltage's indication value is not within the specified setting range at the instantaneous that the high-voltage is cut off, it shall consider that the overvoltage protection device is not well adjusted or failed.

During the test, it may not connect the generator. The controller is tested separately. plugged into the power supply. Use a grounding resistance meter to measure the resistance between any possible live parts of the controller enclosure and the power grounding terminal.

5.18 Determination of insulation strength of low-voltage

circuits Each switch of the controller is placed in the ON position, but the power plug is not plugged into the power supply. Between each terminal of the individual circuit and the grounding terminal of the enclosure, use a withstanding voltage tester which has a power of not less than 0.5 kW and an approximate sine wave to perform test. The test voltage is as shown in Table 5. The test voltage is gradually increased to the maximum value within 5 s to 10 s. After the test for 2 min, it is gradually decreased to below the test voltage and disconnects the test voltage within 5 s ~ 10 s.

5.19 Determination of insulation strength of high-voltage

circuits Cold state overvoltage test. The high-voltage switch is in the ON position, the test voltage is applied to all high-voltage circuits, the test voltage is as shown in Table 6. The test voltage is gradually increased to the maximum value within 5 s ~ 10 s, which is maintained for 1 min. The test voltage maintenance time is as specified in the technical conditions (if the standard has special requirements, it can be carried out in accordance with the requirements of the components).

After the test, gradually decrease it to below the working voltage within 5 s ~ 10 s, disconnect the test power supply. Hot state test. Adjusted over temperature protection, it can increase temperature either naturally or relying on external heat source (or equivalent method). Make the internal temperature of the X-ray generator reach to 60 °C ± 5 °C, perform the test as described above.

5.20 Determination of primary insulation resistance of filament

transformer to ground The controller switch is in the ON position, but the power plug is not plugged into the power supply, use a 1.0-grade 500 V insulation resistance meter to measure the insulation resistance. selects +55 °C, low temperature selects -10 °C.

5.26 Packaging test

It is tested in accordance with the test method of JB/T 9329. The spray time is 30 min.

5.27 Normal working test when power supply voltage fluctuates

After making the connection as shown in Figure 8, make the power supply voltage adjustment button on the controller of the X-ray machine in the normal position, so that the voltage indication value is the power supply rating (such as 220 V for single phase), adjust the tube-voltage to the rated value, the tube-current to the rated value, the exposure time to the rated value, to perform the simulated exposure test at rated working state. Adjust the voltage regulator so that the voltmeter indication value is 90% of the power supply rating (such as 198 V for single phase). It may adjust the power supply voltage adjustment knob on the X-ray machine's controller, to repeat the simulated exposure test under rated working state. Adjust the voltage regulator so that the voltmeter indication value is 110% of the power supply rating (for example, 242V for single phase).

It may adjust the power supply voltage adjustment knob on the X-ray machine's controller, to repeat the simulated exposure test under rated working state.

Figure 8 -- Schematic diagram of the electrical connection of the instrument During the test, there shall be no phenomenon of test interruption, otherwise, it is considered to be abnormal.

The supply voltage variation during the test shall be less than 2.5%. The test can be carried out simultaneously with the penetration test, the transillumination sensitivity test and the like. The simulated exposure test under rated working state during the test means that the test is carried out when the tube-voltage, tube-current, and exposure time are all rated values, but the film is not placed. Power supply ~ Voltage regulator X-ray machine

7.1 Marking

7.1.1 The obvious location of the generator's outer surface shall be sprayed the mark of "paying attention to the ionizing radiation", which shall comply with the requirements of Appendix F1 of GB 18871-2002.

7.1.2 The nameplate shall include the following information.

a) Model specifications, product names;

b) Main technical parameters (including rated tube-voltage, rated tube-current, focus size, focus position);

c) The name, address and trademark of the manufacturer;

d) Date and number of exit-factory; e) Certification mark.

7.1.3 The circumferential X-ray machine's generator (at the window) shall have a red ring mark.

7.2 Packaging

7.2.1 The X-ray machines shall use composite packaging in accordance with the relevant provisions of GB/T 13384.

7.2.2 The characters and signs on the outer wall of the package shall be clear and shall not be obscured by the long time, handling friction and rain. The contents include at least.

a) The name and address of the manufacturer;

b) The product name and model specifications;

c) The receiving organization, address and shipping organization, address;

d) The packaging volume (length × width × height);

e) The packaging box shall be marked with the words such as "fragile items", "upward", "avoid rain", "no tumbling", etc., the words or symbols shall be in accordance with the provisions of GB/T 191;

f) Product implementation standard number and name. […]