ECA-EIA-503-A-1990.pdf
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1、Electronic Industries Alliance 2500 Wilson Boulevard. Arlington. Virginia 22201 -3834 703-907-7500 fax 703-907-7501 www.eia.org March 6, 2001 ERRATA TO: Recipients of the February 2001 Reaffirmed ANWEIA-503-A “Recommended Practice for the Measurement of X-Radiation from Direct-View Television Pictur
2、e Tubes“ NOTE: Please replace pages 5 and 6 with the pages attached. Part of the text on page 6, Section 6.5.1 did not print after converting from Word Perfect to Word format when the document was reaffirmed. We are sorry for any inconvenience this may have caused. Sincerely, Phil. CdtofJ Publicatio
3、ns Office Technology Strategy the TV X-1; or the Model 491. Thin window ion chamber survey meter may also be used. See EL4 Consumer Products Engineering Bulletin No. 3 “Measurement Instrumentation for X-Radiation from Television Receivers“. 3.1.2 X-Radiation Measuring Instrument The principal x-radi
4、ation measuring instrument shall comply with the requirements of Title 21, Code of Federal Regulations (CFR), Chapter I, Subchapter J, Section 1020.10, subparagraph (c)-(2), and with EL4 Consumer Products Engineering Bulletin No. 3. The instrument shall provide x-radiation measurements (mR/h) in the
5、 range of the applicable limit. The x-radiation sensitive volume shall have a cross-section parallel to the external surface of the hypothetical cabinet of 10 CII? and no dimension larger than 5 cm. Measurement deviations due to instrument imprecision, energy dependence and other sources of error s
6、h d be commensurate with the current instrument art. An example of an instrument that fulfills these requirements is the 440 RF/C. Measurement with instruments having other areas must be corrected for spatial non-uniformity of the radiation field to obtain the exposure rate averaged over a 1 0 cm2 a
7、rea. NOTE: A larger area detector may be used, provided that the field is determined to be uniform over its aperture. Examples: 440 RF, A and TV-150. 3.2 Test Equipment Stabie electronic conditions must be provided for the operation of the tube under test and to measure anode voltage and current. 3.
8、2.1 Anode Voltage Metering System The recommended anode voltage metering system incorporates a very stable and accurate high voltage divider and voltmeter w i t h an overail accuracy of 0.1% and a digital readout using at least four signifcant figures, having a sensitivity of at least 0.01 kV. (The
9、effect of the overall accelerating potential on the x-radiation characteristics is such that the x-radiation exposure rate could double for each 1 kV change of accelerator potentia thereby making accurate voltage measurements desirable.) If the recommended accuracy of the measurement system cannot b
10、e achieved, the inaccuracy shall be accounted for by reducing the recorded voltage reading by the maximum possible measurement deviation. Copyright Electronic Components, Assemblies & Materials Association Provided by IHS under license with ECA Licensee=IHS Employees/1111111001, User=Wing, Bernie No
11、t for Resale, 03/30/2007 00:15:25 MDTNo reproduction or networking permitted without license from IHS -,-,- E I A 503-A S O - 3234600 0073968 7 ! 5.1 Tube Position 4 I 5.2 External Components Q I 5 . 3 Warm-up EIA-503-A Page 3 3 . 2 . 2 Anode Current Metering System The recommended current metering
12、system incorporates an overall accuracy of & 1%. (The effect of the anode current on the x-radiation characteristics is that the x-radiation exposure rate is directly proportional to the anode current.) if the recommended accuracy of the anode current measurement system cannot be achieved, the inacc
13、uracy shall be accounted for by reducing the recorded current reading by the maximum possible measurement deviation. Power Supply for the Overall Accelerating Potential The recommended power supply for the overall accelerating potential incorporates a stabaty of 0.05%. (The effects of the overall ac
14、celerating potential on the x-radiation characteristics i s i n accordance with paragraph 3.2.1, thereby making a stable power supply desirable.) If the recommended stability of the power supply cannot be achieved, the variation shall be accounted for by recording the lowest voltage reading during a
15、 specific x-radiation measurement. 3 . 2 . 3 3 . 2 . 4 Anode Connector Assembly See paragraphs 6.2 and 6.3. 4 . CALIBRATION 4 . 1 The measuring instrument shall be calibrated by exposure to a uniform x-ray field having an exposure rate and energy representative of those to be measured. 4.2 The calib
16、ration shall be traceable to the National Institute of Standards and Technology (NIST). 5. TEST CONDITIONS The tube under test shall be positioned relative to the test equipment so that measurements may be made as specified in paragraph 6.0. External components normally mounted on the tube may be in
17、 place while obtaining x-radiation characteristics. (External components may include deflection yokes, aiignment c o i l s , mounting hardware, implosion protection mechanisms, etc.) A warm-up period shall be provided for both the tube and test equipment in order to obtain stable operating condition
18、s before proceeding with the measurement. Anode current shali not vary or drift more than & 1% while measurements are being made. 5.4 Display 5 . 4 . 1 Focus The tube under test s h d be operated at optimum focus. Copyright Electronic Components, Assemblies & Materials Association Provided by IHS un
19、der license with ECA Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/30/2007 00:15:25 MDTNo reproduction or networking permitted without license from IHS -,-,- EIA 503-A 90 3234b00 007L9b9 9 EIA-503-A Page 4 5.4.2 Blanking The tube shall be operated with dc voltages which res
20、ult in an unblanked raster. 5 . 4 . 3 Multiple Guns Multiple gun tubes may be operated using only one gun. 5.4.4 Raster Geometry The horizontal and vertical scan controls shall be adjusted so that the raster width and height coincide with the screen width and height. The linearity of the scan shall
21、be checked and adjusted with a crosshatch pattern such that the distance between crosshatch lines measured along the major and minor axes shall be within +. 10% of the corresponding measurements at the center of the screen. The radius of curvature of all four ( 4 ) raster sides shall not be less tha
22、n 200 cm. The horizontal and vertical raster dimensions shall then be increased by 10% while maintaining the established linearity. 6 . PROCEDURE The x-radiation exposure rate shall be measured as described below at the location of maximum intensity. The background radiation shall be verified at the
23、 test position and corrections applied to the observed data as required. 6 . 1 Radiation from the Tube Face The radiation from the tube face shall be measured with the effective center of the detector 5 cm from the surface of the tube. NOTE: When the plastic spacers on the 440 RF/C Survey Meter are
24、in contact with the tube face or the surface of the hypothetical cabinet, the distance from the surface to the effective center of the detector is 5 cm. The measured area of the tube face must be extended past the extremities of the actual faceplate to completely enclose the effective volume of the
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