ASTM D483 Test Method for Unsulfonated Residue of Petroleum Plant Spray Oils
6. Apparatus
6.1 Sulfonation Flask - The flask is shown in Fig. A1.1 and described in Annex A1.
6.2 Meniscus Viewing Lens, focusing type, consisting of eyepiece and objective to facilitate reading the meniscus with a minimum of parallax, is recommended.
6.3 Water Baths - Two water baths maintained at 25 more or less 0.5°C and 99.5 to 100°C, and conforming to the requirements prescribed in Annex A1.
6.4 Shaking Machine - The exact design described in the appendix is required for uniform control of shaking and precision results. Hand shaking is permissible if technique is developed to correlate results by machine shaking.
6.5 Centrifuge - A centrifuge as described in Annex A1 is recommended.
7. Reagents
7.1 Purity of Reagents - Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination.
7.1.1 Commercially prepared solutions may be used when they meet or exceed the specifications set in 7.1.
7.2 Fuming Sulfuric Acid (approximately 15 % free SO3). (Warning - See 7.3 and 7.4.)
7.3 Sulfuric Acid (98.61 %) - Prepare by blending reagent-grade fuming and concentrated sulfuric acids to a concentration of 98.61 more or less 0.1 % H2SO4 as determined by titration. (Warning - Corrosive. Health hazard. Oxidizer.) (Warning - While preparing the reagent, protect the face with a safety mask and place the flask in a tray.)
7.4 Sulfuric Acid (sp gr 1.84, approximately 95 %) - Concentrated sulfuric acid (H2SO4). (Warning - Corrosive. Health hazard. Oxidizer.).
8. Reference Spray Oil
8.1 Test results for unsulfonated residue are highly dependent upon rate of shaking. A reference spray oil has been calibrated for unsulfonated residue by a group of cooperating laboratories using both machine and hand shaking. Instructions are given in Section 8 for using this reference oil as a guide to ensure that the rate of shaking is correct.
9. Calibration
9.1 Machine Shaking Rate - A rate of 425 cycles/min was used in the cooperative work to establish the unsulfonated residue of the reference spray oil. There are small variations in severity of shaking between individual machines, even when they are newly built and of the same make; and these differences can increase with use. Consequently, each laboratory shall run occasional tests on the reference spray oil. If an unsulfonated residue is found which differs by more than more or less0.4 % from the established value, the rate of shaking shall be adjusted accordingly. A faster rate tends to give a lower unsulfonated residue, and vice versa.
9.2 Hand Shaking Rate - Each operator shall standardize his technique of shaking so as to obtain the established value (within more or less 0.4 %) on the reference spray oil. A rate of 300 cycles/min was used in the manual shaking tests in the cooperative program on the reference oil; however, an individual operator's calibrated rate can differ appreciably from 300 cycles/min.
10. Sampling
10.1 Obtain a sample for this test method using Practices D4057 or D4177.
