GB 9254.2 standard difference before and after version change_Century Wisdom (Suzhou) Testing Technology Co., Ltd

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GB 9254.2 standard difference before and after version change

Release time:

2023-05-18 15:21

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　　1 Changes in the scope of application

The new version of the standard GB/T 9254.2-2021 "Information technology equipment, multimedia equipment and receiver electromagnetic compatibility part 2: immunity requirements" as a set of information technology equipment, multimedia equipment and receiver integrated electromagnetic compatibility immunity standard, can more conveniently solve the problem of standard applicability of such multi-functional products.

The GB/T 9254.2 standard was released on December 31, 2021 and officially implemented on July 1, 2022. Compared with GB/T 17618 and GB/T 9383, there are great changes in the scope of application and test items. as shown in Figure 1.

Fig. 1 Comparison of Application Scope

　　2 Changes in test items

The biggest change of GB/T 9254.2 standard in test items is to cancel the input immunity, shielding effect, radio frequency electromagnetic field keying carrier and other immunity test items of GB/T 9383 standard, and increase the immunity test items of broadband pulse conduction disturbance, as shown in fig. 2.

Figure 2 Change of test items

　　3 Test requirements

3.1 test arrangement

The EUT test layout shall be carried out according to Fig. 3.

If the EUT specification or user manual includes the use of external protective devices or special measures to achieve explicit requirements for EMC compliance (such as additional grounding), the test shall be carried out with these devices or measures.

If the EUT is equipped with cables for testing, these cables shall be used for testing. If no cable is provided, a suitable type of cable suitable for signal transmission shall be used and comply with any special requirements specified in the user's documents or manuals. Spiral cables (e. g. keyboard cables) shall not be intentionally stretched during the test. For such a cable, the length specified in the table is the unstretched length.

If there is a separate ground in addition to the ground provided by the power cable, the ground shall be installed in accordance with the EUT specification during all tests. Equipment with dedicated AC/DC power converters shall be tested as AC powered equipment. If possible, use the power converter that is used with the EUT.

Fig. 3 EUT Test Layout

Requirements for 3.2 test items

According to different ports, the requirements of each test item are shown in Fig. 4 ~ Fig. 7. During the test, the main functions shall be monitored and evaluated according to the relevant performance criteria.

The immunity tests shall be carried out separately in any order. The same sample shall be used for all tests related to a specific electromagnetic phenomenon (test item), and other samples may be used for tests of different electromagnetic phenomena.

Fig. 4 Shell Port Immunity Requirements

Figure 5 Analog/Digital Data Port Immunity Requirements

Fig. 6 Immunity Requirements of DC Network Power Port

Fig. 7 AC Power Port Immunity Requirements

Compared with GB/T 17618 and GB/T 9383, GB/T 9254.2 has different test requirements for each immunity test item in Fig. 4 ~ Fig. 7, as follows:

A. Electrostatic discharge test. In GB/T 9254.2 standard, the number of test points is no longer specified, but depends on the specific equipment. It is only clear that the selection of test points should pay special attention to the keyboard, dial, power switch, mouse, drive slot, card slot, area around the communication port, etc. In GB/T 17618 standard, for the conductive surface, the contact discharge and the number of indirect contact discharge points on the coupling plate are clearly required. The equipment under test shall be subjected to at least 200 electrostatic discharges, of which 100 are positive and negative, and shall be carried out on at least 4 test points of the equipment under test. If there is no applicable direct contact test point, at least 200 discharges shall be carried out in the form of indirect discharge.

B, continuous radio frequency electromagnetic field disturbance test, in GB/T 9254.2 standard, the test frequency range is 80MHz ~ 6GHz, and in GB/T 17618 standard, the test frequency range is 80MHz ~ 1GHz.

C, continuous radio frequency induced disturbance test, in GB/T 9254.2 standard, 0.15~10MHz is 3V; In the frequency range of 10~30MHz, the test level is 3~1V (the amplitude of the test level decreases linearly with the logarithm of the frequency); In the frequency range of 30~80MHz, the test level is 1V, as shown in Figure 8. In the GB/T 17618 standard, the test level is 3V.

Fig. 8 Continuous RF Induced Disturbance Level

D, surge (impact) test, in GB/T 9254.2 standard, for the AC power port, apply 5 positive pulses when the phase is 90 °; Apply 5 negative pulses when the phase is 270 °. However, there is no clear stipulation in GB/T 17618 standard.

E, power frequency magnetic field test, in GB/T 9254.2 standard, it is clear that the proximity method can be used. In the GB/T 17618 standard, it is clearly required to use the immersion method for testing.

F, broadband impulse noise disturbance for GB/T 9254.2 standard newly added immunity test items. Applies only to the CPE (Client Equipment) xDSL port.

3.3 performance criterion

The general performance criterion is divided into: performance criterion A, performance criterion B and performance criterion C.

Performance Criterion A: The equipment can continue to operate as expected without operator intervention. When the equipment is used as intended, there will be no degradation in performance, loss of function or change in operating state below the performance level specified by the manufacturer.

Performance Criterion B: During the application of disturbance, performance degradation is allowed. However, after the test, there shall be no unexpected changes in the actual operating state or stored data. After the test, the equipment can continue to operate as expected without the intervention of the operator. When the equipment is used as expected, there should be no performance degradation or functional loss below the performance level specified by the manufacturer.

Performance Criterion C: Loss of function is allowed, provided that the function can be restored on its own, or can be restored by the user by operating the controller or restarting according to the manufacturer's instructions.

If you need more information about electromagnetic compatibility testing, you can visit the company's website http://www.emc-mall.com/查看。

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