GB/T 11755.2-1989 Medical diagnostic X-ray machine tube current test method GB/T11755.2-1989 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Methods for the measuring of tube current ofmedical diagnostic X-ray equipmentSubject content and scope of application
This standard specifies the tube current measurement method, test result calculation and evaluation of medical diagnostic X-ray equipment. GB 11755.2--89
This standard applies to the tube current measurement of medical diagnostic X-ray equipment during product identification test, factory inspection and type test. This standard does not apply to the tube current measurement of medical diagnostic X-ray equipment using grid-controlled X-ray tube. 2 Reference standards
GB11757 Exposure time measurement method for medical diagnostic X-ray equipment3 Test conditions
3.1 Environmental conditions
The ambient temperature is 15~35℃,
the relative humidity is 45%~75%,
C. The atmospheric pressure is 86×103~106×103Pad. No corrosive and explosive gas and dust. 3.2 Power supply conditions
During the test, the apparent internal resistance of the X-ray machine power supply should be adjusted to the value specified in the relevant product standards, and the allowable error of its internal resistance is a,
± 5%.
b, Fluctuation range of power supply voltage: For single-peak high-voltage generators without power supply voltage fluctuation compensation, the test should be carried out under the condition of 100%±1% of the nominal power supply voltage when the power supply is unloaded. For all other high-voltage generators, the test should be carried out under the condition of 100%±5% of the nominal power supply voltage when the power supply is unloaded. c, The power supply voltage waveform is a substantial sine wave. d. The change in the power supply voltage frequency does not exceed ±1% of the rated value of 50Hz. 3.8 High-voltage cable length bzxZ.net
If there is no special provision in the technical documents of the machine being tested, in addition to using the original machine high-voltage cable during the test, the length of the high-voltage cable connected between the voltage divider and the X-ray source assembly should not be longer than 1.5m each. 3.4 Thermal balance
The high voltage generator of the X-ray machine should be tested in a thermal equilibrium state. Unless otherwise specified, the high voltage generator of the X-ray machine under test can be considered to be in a corresponding thermal equilibrium state after working for 0.5h at a load of 60% to 100% of the nominal output of the fluoroscopy. 3.5 Tube voltage error
The tube voltage value at each tube current value should be within the error range specified by the X-ray machine under test. 4 Test instruments
4.1 When the exposure time is greater than the damping time of the milliammeter, a milliammeter (magnetoelectric DC meter) or a sampling milliammeter can be used. 4.2 When the exposure time is less than the damping time of the milliammeter, a milliammeter stopwatch or a sampling milliammeter can be used. If a milliampere stopwatch is used for measurement, the test instrument of the light time shall comply with the relevant provisions of GB11757, which was approved by the State Administration of Technical Supervision on October 20, 1989 and implemented on July 1, 1990. 4.3 The error of the measuring instrument and method shall not exceed one third of the allowable error of the measured value. 5 Test method 5.1 Adjust and test the power supply internal resistance of the machine so that it reaches the value range specified in the product standard. 5.2 Before starting the test, it is allowed to adjust the tube voltage and tube current value indication value once according to the installation and debugging method in the manual. 5.3 When the machine allows 220V/380V two power supplies or other power supplies, it should be tested under each power supply condition. When changing the power supply specification, it is allowed to readjust once according to the provisions of 4.1 and 4.2. 5.4 Connect the test instrument in series to the high-voltage circuit of the rectified high-voltage generator device, or to the monitoring point specified in the machine manual. The test method should be described in the random documents. 5.5 Put the machine in a thermal equilibrium state.
5.6 For X-ray machines without filament voltage stabilization devices, continuous indicating instruments or sampling milliammeters should be used. If a sampling milliammeter is used, the sampling delay time should not be less than 100ms.
5.7 Combination of loading factors during the test
5.7.1 The combination of loading factors for determining the tube current PAE for intermittent operation is shown in Table 1. Table 1
Nominal tube voltage
Note: 1) The higher of the two is selected.
Nominal tube voltage
50% of the nominal value
or minimum tube voltage
Nominal tube voltage
Current value when the nominal electric power is 50%2)
2) When the milliampere number of the machine is inconsistent with the provisions in the table, the milliampere range that is closer to it shall be selected. The combination of loading factors for determining the tube current PAE for continuous operation is shown in Table 2.5.7.2
Nominal tube voltage
Note: 1) The higher of the two shall be selected.
Nominal tube voltage
Specified maximum and minimum tube voltages
25% of the specified maximum X-ray tube current or 0.5mA and the maximum tube current2) 2) For a fixed combination of high-voltage generating devices, the tube current shall not be less than 0.5mA when the tube voltage value can be achieved. The number of loading repetitions in the test is 10 times. 6 Calculation and evaluation of test results
GB 11755.2—89
6.1 When calculating the tube current error of the specified machine, the average error percentage is calculated as follows: Ip-
Where: PAE
The average error percentage of 10 observations,
Ip predicted value,
-arithmetic mean of sampling observations.
×100%
6.2 The test results include the test instrument error and the test method error. Additional remarks:
This standard was proposed by the National Technical Committee for Standardization of Medical Electrical Appliances. This standard is under the jurisdiction of Liaoning Medical Device Research Institute. This standard was drafted by Southwest Medical Equipment. The main drafter of this standard is Sun Jiaxiu.
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.