黑度计校验规程.doc

NJBST Co.,Ltd. QCD-016 Rev.:0 Page:1 of 3 Title: DENSITOMETER CALIBRATION PROCEDURE DENSITOMETER CALIBRATION PROCEDURE 黑 度 计 校 验 工 艺 规 程 CONTROLLED 在控本□ UNCONTROLLED 非在控本□ COPY NO 副本编号： PREPARED BY 编制： DATE 日期： REVIEWED BY 审核： DATE 日期： APPROVED BY 批准： DATE 日期： NJBST Co.,Ltd. QCD-016 Rev.:0 Page:2 of 3 Title: DENSITOMETER CALIBRATION PROCEDURE 1. Scope This procedure covers the calibration of transmission densitometers used to perform radiographic film density measurements and provides a means of evaluating the reliability of transmission densitometers used for the measurement of radiographic film density. This procedure is prepared reference to SE-1079 STANDARD PRACTICE FOR CALIBRATION OFTRANSMISSION DESITOMETERS of ASME Sect.Ⅴ. 2. Apparatus 2.1 Apparatus should consist of the following: 2.1.1 The X-ray film step tablet standard of the National Center of Measuring having at least 5 steps with neutral densities from at least 1.0 through 4.0. The calibration of the step wedge film shall have been verified within the last 12 month by comparision with a National Center of Measuring serialized step tablet. 2.1.2 Transmission Densitometers with digital readout displays specifically manufactured for the purpose of measuring the range of film densities, described in 2.1.1 shall be used. 2.1.3 Manufacturers Operating Instruction for Appropriate Transmission Densitometer. 3. Calibration 3.1 Full-scale linearity calibration of densitometer shall be performed at least every 90 days during use. 3.1.1 Allow a minimum of 30min warm-up time. After this warm-up period, adjust the 0 reading of the densitometer. 3.1.2 Select and position for reading the neutral density closest to 1.0，2.0，3.0，4.0 on the calibrated step tablet. Read and record the density for each step. 3.1.3 Compare the densities recorded with the actual density value