1、 ENGINEERING STANDARDS Test Procedure SUPERCEDED EDS-T-7720 The Method for pH of Aqueous Solutions This standard may be applied only for current projects. It is Superceded for all future projects and replaced by ASTM D1287. pHF ?U9I - Note: 8 E:48t G8 =97 FF7 957%L+ , FG P-P Program .Bd# ASTM D1287
2、) $4=F7 957F$ . Copyright 2011 General Motors Company All Rights Reserved August 2011 Originating Department: GM Korea Engineering Standards Page 1 of 4 Version : 4 1 Scope Note: Nothing in this standard supersedes applicable laws and regulations. Note: In the event of conflict between the Korean an
3、d English language, the Korean language shall take precedence. 1.1 Purpose. This standard aims at specifying the test method for pH of aqueous solutions. 1.2 Applicability. This standard applies to measurement of pH values of brake fluid, nonfreezing solution and other aqueous solutions. 2 Reference
4、s Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ASTM E 70 KS M 0011 2.2 GM Standards/Specifications. None 2.3 Additional References. None 3 Resources 3.1 Equipment. 3.1.1 pH Meter. It consists of a detecting part made of gl
5、ass electrodes and reference electrodes and an indicating part showing the detected potential differences. Depending on the need, a detector for correcting temperature may be added to the detecting part, and a regulator for compensating unsymmetrical difference and a dial for correcting temperature
6、or for sensibility control to the indicating part. 3.1.1.1 Performance of Glass Electrodes. The glass electrode shall meet the specifications in Table 1. 1 P7 :0 : ., E:48 6&F !7$ :4-8! 9I8x $4=F 3L 6$ . :0 : F67t 7568 18 88x 7 , F6* 72T8p) F$ . 1.1 +95 . ., E:48t 3L768 pHF8x ?U9IFd 88F 4G -7 $4F 9I
7、F$ . 1.2 957 -88 . /)07 38%P E:48x 957F$ . 2.1 17 E:4 / . ASTM E 70 KS M 0011 2.2 GM E:4 / . None 2.3 dA E:4 / . None 3 4G 88 3.1 4G 8/x . 3.1.1 pH Meter. 8T*98-0 d:4 98-8p) %P . , %P 9888=* :4F# :4.) 2e%L6 8 , .7# Fx77 &d( 7$ .(9I7 :. , :4.7# /x$4? 9888 .(17 99.* :*3L) 3G 81 6o8t G !F 98) $#$ . 4.2
8、1.3 pH 7 E:4 768x /x87 .4 .H 8l 3L 8 &d* -Ld) -LF7 pHF8x ?U9IF$ . GM KOREA ENGINEERING STANDARDS EDS-T-7720 Copyright 2011 General Motors Company All Rights Reserved August 2011 Page 3 of 4 Version : 4 4.2.1.4 Take the detecting part out of the beaker after adjusting the zero calibrating dial to pH
9、 7, and wash the part with distilled water and dry with clean paper. 4.2.1.5 Conduct the operation in 4.2.1.3 with a solution of pH 4. 4.2.1.6 Take the detecting part out of the beaker after adjusting the tune control dial to pH 4 and wash the part with distilled water and dry with clean paper. 4.2.
10、1.7 Calibrate the pH meter by repeating the operations from 4.2.1.3 to 4.2.1.6 three times. 4.2.1.8 Conduct the operation in 4.2.1.3 with sample solution to read pH value. 4.2.2 Measurement of pH Values of Solutions with pH 7 min. 4.2.2.1 Get the pH values by conducting the operations from 4.2.1.3 t
11、o 4.2.1.8 with reference solutions of pH 7 and 9. 5 Data 5.1 Evaluation. pH value of a sample solution is acquired by the following formula and indicated on an indicator. )10ln()()(uuuu TRFEEpHpH SS Where, pH: pH value of sample solution. pH(S): pH value of reference solution. E: Electromotive force
12、 of an electric cell in sample solution. Es: Electromotive force of an electric cell in reference solution. R: Gas constant 8.3044 J K-1 mol-1. T: Absolute temperature T = t E + 273.15. F: Faraday constant 96487 C mol-1. 6 Safety This standard may involve hazardous materials, operations, and equipme
13、nt. This standard does not propose to address all the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 7 Notes 7.1 Glossary. pH:
14、Values that represent the acid or alkali radical. These shall be presented as the logarithm of the reciprocal hydrogen ion exponent. 4.2.1.4 759D .(9I $868x 17F7 pH 7 ) 99.* 7672P !6 :*3L) 8 6o !F 98) $#$ . 4.2.1.5 pH 4 768x 17F7 4.2.1.3 8 988x F$ . 4.2.1.6 -,2l 99.* 7672P !6 :*3L) 8 6o !F 98) $#$ .
15、 4.2.1.7 4.2.1.3 4.2.1.6 8 988x 3G -L.)F7 pH Meter* .(9IF$ . 4.2.1.8 4* 3L768p) 4.2.1.3 8 988x F7 pHF8x 8#$ . 4.2.2 pH 7 818 3L768 pHF ?U9I . 4.2.2.1 pH 70 pH 9 E:4 768x 17F7 4.2.1.3 4.2.1.88 988x F7 pHF8x ?U9IF$ . 5 4G $8Bd 5.1 D4 . 4*8 3L768 pH F8t $88 47 8F7 , F8 1%L6 :47 E4%P$ . )10ln()()(uuuu T
16、RFEEpHpH SS 7 d2P , pH: 4*8 3L768 pH F . pH(S): E:4 768 pHF . E: 4* 3L768 272P8 98:8 d98)Y . ES: E:4 76 272P8 98:8 d98)Y . R: d=13L 8.0344 J K-1mol-1. T: 9) 9P9I / -PF%L6$ . Issue / P9I8)Y Publication Date / 38 88 Description (Organization) / 9PP9I76 (:04.2P ) 4 AUG 2011 Apply new Engineering Standard Template. Superceded (Polymer / Organic Material Lab Team) / 4 d3TE:4 64 957 . F9I957 =* (G)8*4G D4 )
