GOST 16321.2-70
GOST 16321.2−70 Silver-copper alloys. Method of spectral analysis (with Amendments No. 1, 2)
GOST 16321.2−70*
Group B59
STATE STANDARD OF THE USSR
SILVER-COPPER ALLOYS
Method of spectral analysis
Silver-copper alloys. Method of spectral analysis
AXTU 1709
Date of introduction 1972−01−01
Resolution of the Committee of standards, measures and measuring devices under Council of Ministers of the USSR from 26. VIII 1970 N 1328 the date of the entry is set with 01.01.72
Proven in 1985 by the Resolution of Gosstandart from
_______________
** Expiration removed by Protocol No. 5−94 of the Interstate Council for standardization, Metrology and certification (I & C N 11/12, 1994). — Note the manufacturer’s database.
REPLACE GOST 7979−56 in part of sec. IV-VIII
* REVISED (July 1986) with Amendments No. 1, 2 approved in August 1980, February 1985 (IUS 10−80, 5−85).
This standard applies to silver-copper alloys and establishes a spectral method for the determination of bismuth, antimony, lead and iron (at mass fraction of bismuth, antimony and lead from 0.001 to 0.01% iron and from 0.005 to 0.25%).
The method is based on measuring the intensity of impurity lines in an arc spectrum. Quantification of mass fraction of impurities is carried out by the method of three references. The electrodes were applied to the rods of the analyzed alloy.
Application of the method provided for in the standards and specifications that establish technical requirements for products.
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 22864−83.
2. APPARATUS, REAGENTS AND SOLUTIONS
Quartz spectrograph medium dispersion.
Arc generator of alternating current.
Microphotometer.
Clips for electrodes with water cooling.
Photographic plates of the spectral type II sensitivity of 10−15 conventional units.
Standard samples of the enterprise.
Developer and fixer — GOST 10691.0−84, GOST 10691.1−84.
3. PREPARATION FOR ASSAY
Samples and standard samples should be in the form of two cast rods with a diameter of 6 mm and a length of 20−30 mm. Rods with both ends sharpened to a hemisphere or a truncated cone with ground diameter of 1.5−1.7 mm.
To remove surface contamination, the samples were placed in a glass, pour diluted 1:1 hydrochloric acid, boil for 2 min, washed with water and dried.
(Changed edition, Rev. N 2).
4. ANALYSIS
Photographing the spectra produced by the spectrograph at a slit width of the spectrograph 0.015 mm, the distance between the electrodes is 1.5 mm, the strength of the arc current is 5 A, the time of the preliminary firing a 30 second exposure time 45 s. the Interelectrode gap is set by the template. Electrodes serve as cast members. Together with the samples on the same plate photographed spectra of standard samples analyzed grade alloy.
For each sample and the standard sample receive four parallel spectrogram.
Photographic plates showing within 3 min when the temperature of the developer is 18−20 °C. the Shown plate is rinsed in water, fixed, washed in running water, dried and photometric.
(Changed edition, Rev. N 2).
5. CALCULATION OF RESULTS OF ANALYSIS
Analytical lines are recommended to perform the analysis, the range of detectable concentrations of impurities listed in the table.
The designated element | Wavelength of lines of the designated element, nm | The elements of comparison | The range of detectable concentrations, % |
Bismuth | 306,77 | Background the short wavelength side |
0,001−0,01 |
Lead | 283,31 | Background in the long wavelength side |
0,001−0,01 |
Iron | 259,94 | The same |
0,005−0,05 |
The same |
0,05−0,25 | ||
Antimony | 259,81 | Background the short wavelength side |
0,001−0,01 |
For all impurities, the element of comparison is the background of the continuous spectrum. The background value should be in the region of normal pochernenija.
Mass fraction of impurities was determined by the three standards with the objective photoretrieval. The calibration graphs are built for each analyzed element. The ordinate of the delay values of the logarithm of the relative intensity of the impurity lines and the background, and the abscissa shows the values of the logarithm of concentration of standard samples.
With the help of calibration curve by the known values of the logarithm of relative intensity find the mass percent of impurities in the sample.
The convergence of the results of parallel measurements is characterized by a relative standard deviation equal to 0.20.
(Changed edition, Rev. N 2).