ISO 911:1977 pdf download.Sulphuric acid for industrial use - Evaluation of sulphuric acid concentration by measurement of density
1 SCOPE AND FIELD OF APPLICATION
This International Standard specifies a method for the approx imate evaluation of sulphuric acid (H2SOg) concentration of sulphuric acid for industrial use, by measurement of density.
2 PRINCIPLE
Determination of the density at 20 °C by means of a hydrometer. Evaluation of the corresponding sulphuric acid (H,SOg) concentration.
3 APPARATUS
Ordinary laboratory apparatus and 3.1 Hydrometer, graduated in 0,005 g/ml，calibrated at 20 °C (see ISO/R 649).
3.2 Glass test tube, of capacity at least 500 ml, of diameter at least 25 mm greater than that of the hydrometer (3.1), and of height at least 25 mm greater than the immersion level of the hydrometer.
4.1 Determination of density
Place approximately 500ml of the test sample in the glass test tube (3.2). Adjust the temperature of the contents of the test tube to 20±0,5 °C.
Plunge in the hydrometer (3.1) and, as soon as static equilibrium has been reached, verify again that the temper-ature of the acid is 20±0,5 'C. Read the density indicated on the hydrometer scale.
4.2 Evaluation of sulphuric acid (H2SO4) concentration
Read from the table the concentration corresponding to the density indicated on the hydrometer.
5 EXPR ESSION OF RESULTS
State the density read on the hydrometer, expressed in grams per millilitre, and the corresponding sulphur ic acid (H2SO4) concentration obtained from the table.
6 TEST REPORT
The test report shall include the following particulars :
a) the reference of the method used;
b) the results and the method of expression used;
c) any unusual features note during the deter-mination;
d) any operation not included in this International Standard or regarded as optional.ISO 911 pdf download.