SH/T 0193-1992 Determination of oxidation stability of lubricating oils — Rotating oxygen bomb method

Summary page. This page is a compiled excerpt/summary of the standard — it is not the full standard text and does not replace it. Verify every value against the official standard and the product certificate before use.

SH/T 0193-1992 specifies the determination of the oxidation stability of lubricating oils with the rotating oxygen bomb, and this page summarizes its historical identity, scope, principle, apparatus, conditions, catalyst, sample preparation, end point, precision and annex equipment.

Evidence note: historical study material for the 1992 edition, which has been replaced by the 2008 edition; neither the full standard text nor a controlled operating procedure, and technical review is pending. The original queries on concentration, dimensions and units are retained, and no product applicability is inferred.

Method identity and historical version: Original PDF 1 and the official 1992/2008 records. SH/T 0193-1992, with the original scanned header using the two-digit year SH/T 0193-92, Determination of oxidation stability of lubricating oils (rotating oxygen bomb method). The original was approved and implemented on 1992-05-20, replacing ZB E34 011-88. The official record shows this edition abolished, and the 2008 record states explicitly that it fully replaces the 1992 edition and was implemented on 2008-10-01. This page only compiles historical study of the 1992 edition; it is not called current, does not replace the entry point of the 2008 edition, and infers no equivalence between the two editions, contractual applicability or product relationship.

Scope and oil restrictions: Original PDF 1, Chapter 1. Used for evaluating the oxidation stability of new and in-service turbine oils of the same composition (base oil and additives); the original also lists rapid evaluation of new mineral insulating oils containing 2,6-di-tert-butyl-p-cresol and batch performance control of oils with specified antioxidants. This edition does not apply to antioxidant-containing insulating oils with a viscosity greater than 12 mm²/s at 40 °C. The same composition is a precondition for applicability, and the method cannot be used to compare the actual service life of arbitrary formulations of different composition. The original gives no specific product numbers available, and this page adds none.

Principle and the starting point of timing: Original PDF 1, Chapter 3 and PDF 4, Chapter 9. The sample, distilled water and copper catalyst are placed in a covered glass sample container, which is put into an oxygen bomb fitted with a pressure gauge; at the specified temperature the bomb is inclined 30° and rotated axially while the pressure is observed against time. The reported result is the time from placing the bomb into the test until the pressure falls 175 kPa from its maximum, in min; timing must not be changed to start only at the maximum pressure point, and the pressure drop is not a final absolute pressure.

Apparatus, reagents and materials: Original PDF 2, Chapters 4–5. This edition uses a mercury thermometer of 100 °C–150 °C with 0.1 °C divisions; a balance with a maximum capacity of 500 g and a sensitivity of 0.5 g; a 5 mL pipette. The copper wire has a purity of 99.9%, is Cu2, with a diameter of 1.50–1.63 mm, and the oxygen purity is 99.5%. The reagents listed are chemically pure 95% ethanol, nitric acid, phosphoric acid and analytical grade potassium hydroxide; the cleaning solvent oil and kerosene follow the standards cited by this edition. The combustion, corrosion and high-pressure risks of the original require actual controlled safe working, and this page does not provide direct operating instructions.

Temperature, pressure and rotation speed: Original PDF 1, 3, Chapters 3/6.4/7.3–7.6. The table below only summarizes the test conditions of the 1992 edition; it is not a product storage temperature or a certificate of instrument manufacturing conformity. The method outline of 100 r/min and the process requirement of 100 ± 5 r/min are kept separate. 7.3 states an initial pressure of 620 kPa at a room temperature of 25 °C and mentions a corresponding increase or decrease of 5 kPa at 25 ± 2 °C; the original gives no complete degree-by-degree conversion procedure, and this page does not generate an automatic pressure correction algorithm. Quantity | 1992 edition clause Insulating oil bath | 140 °C Turbine oil bath | 150 °C Temperature fluctuation | test temperature ±0.1 °C Initial oxygen pressure at 25 °C room temperature | 620 kPa Bomb inclination | 30° to the horizontal Continuous rotation | 100 ± 5 r/min Difference in maximum pressure between the two bombs | not greater than 35 kPa, otherwise the test is invalid End point pressure drop | 175 kPa from the maximum

Catalyst and cleaning solution boundaries: Original PDF 2, 6.1–6.2 and PDF 3, 6.3. The catalyst copper wire is 3 m long, with a coil outer diameter of 46–48 mm and a height of 40–42 mm; the original gives two preparation routes, abrasion and acid treatment, and after treatment the wire may be kept in a desiccator for no more than 24 h, otherwise it must be treated again. The coil preparation requirements for each sample and the weighing requirement after acid treatment must be kept separate. An acid-treated coil whose mass has decreased by 5% from first use cannot continue to be used; pitted or rust-spotted wire must not be used, and treated/weighed wire must not be handled with bare hands. The volume ratio of nitric acid to phosphoric acid is 3:7. The heading of original 6.1 says 10 g/L potassium hydroxide in ethanol but the text says 12 g dissolved in 1 L of 95% ethanol; 7.7 again cites 10 g/L. The internal conflict of the original is retained, and 12 is not changed to 10 or overridden with a new edition formulation.

Test sample and the two water additions: Original PDF 3, 7.1–7.2. The glass sample container holds 50 ± 0.5 g of sample and 5 mL of distilled water; a further 5 mL of distilled water is added to the empty bomb body to aid heat transfer. The position and purpose of the two water additions differ, and they must not be written together as 10 mL inside the sample container. The sample of this edition must be stored in the dark in brown glass bottles. This is a test sample requirement and does not replace the storage and opening restrictions on the label or certificate of a specific product. Sealing, drying and record preparation must follow the complete controlled operating documents.

Oxygen charging and validity: Original PDF 3, 7.3–7.4. The original requires slow flushing twice with oxygen at about 620 kPa, releasing to atmospheric pressure each time, then charging at room temperature as required by this edition; prepare two bombs for the same sample. High-pressure equipment and hot oil bath operations must not be carried out on the basis of this learning page alone. After insertion the pressure rises to its maximum within 15 min and begins to stabilize. If the difference between the maximum pressures of the two bombs is greater than 35 kPa, the test is invalid, and this condition must not be ignored by merely averaging the two time results. The drying requirement after the leak check and the actual equipment applicability must be verified separately.

Rotation, end point and cleaning records: Original PDF 3, 7.5–7.7. The whole test requires the bomb to be fully immersed and rotated continuously and uniformly; perceptible fluctuations in speed affect the result. After the pressure falls 175 kPa from the maximum, record the time and curve, end the test and handle the apparatus according to the original procedure. Original 7.6 contains wording on cleaning while hot, and this page does not use it to write a directly executable hot-oil/flammable-solvent procedure. Residual gas discharge, cleaning and removal of acid residues must follow confirmed safety documents; observe and record the condition of the sample and the copper catalyst.

Precision and the square root: Original PDF 3, Chapter 8, PDF 4, 8.1–8.2. The precision of this edition applies to test times of 40–370 min, and the original gives the 95% confidence level. The repeatability limit is r = 1.58 × √X̄, where X̄ is the arithmetic mean of two results by the same operator; the reproducibility limit is R = 0.20 × X̄, where X̄ is the arithmetic mean of results from two laboratories. The square root in the original figure must not be omitted, and the coefficients of the 2008 edition must not be substituted for this edition. The above limits are a basis for comparing method results, not batch certificate uncertainty, product guarantee values or universal service life. No extrapolation outside the range, and no calculator is released.

Results and reporting: Original PDF 4, 9.1–9.2. Read the outer turn of the pressure-time curve and obtain the time for each bomb from the specified start and the 175 kPa drop end point; the arithmetic mean of the two test results is the rotating oxygen bomb oxidation stability of the sample, expressed in min. Historical records should retain the identity of the 1992 method used, the sample and its composition, the test temperature, the validity of both bombs and the original curves. The method time is not the actual remaining service time of the oil, and this page does not infer equipment service life or acceptance of a specific batch.

Annex equipment boundaries: Original PDF 5–8, Annex A (supplementary item). Annex A covers the oxygen bomb, glass sample container, pressure gauge and test oil bath. The glass sample container has a capacity of 175 mL, a wall thickness not exceeding 2.5 mm and a mass not greater than 100 g; the pressure gauge has a range of 0–1400 kPa and accuracy class 2.0. The oil bath is at least 230 mm deep and at least 30 L in capacity, the bomb is immersed at least 25 mm below the liquid surface, and returns to the test temperature 10–15 min after insertion. The bomb pressure resistance clause of 150 °C/3450 kPa is an equipment requirement, not the 620 kPa oxygen charging pressure or the pressure gauge range. The structural dimensions of Figures A1–A4 and the record paper are not rebuilt item by item and are not used for manufacture, acceptance or actual operation. The queries between the 6.4 mm inner diameter of A1.2 and 6.35 mm in Figure A2, and between the 25 kPa divisions of A3 and the parenthetical 5 psi, are retained and not unified on one's own initiative.

References and items to be verified: Original PDF 1, Chapter 2 and PDF 8, additional notes. This edition cites GB 253, SH 0004 and SH 0005; the additional notes refer to ASTM D2272-85 and ASTM D2112-81, without claiming equivalence or current status on that basis. The currently cited standards and contractual requirements must be verified separately. The eight physical pages are printed 569–576 of a bound volume, and Chapters 1–9 and Annex A have been located. Having read the original does not mean that all equipment dimensions, operational risks or technical applicability have passed review. The cleaning solution concentration, pressure units and dimensional queries are all retained; the original PDF/OCR is read-only and the scans are not published.

Direct answers to common questions: Original PDF 1, 3–4, 7–8. Can the 1992 edition be treated as current? No, it has been officially abolished and the 2008 edition explicitly replaces it; this page is historical study only. Is the repeatability 1.58 times the mean? No, the original figure is 1.58 times the square root of the mean. Does timing start at the maximum pressure? No, the original reports from placing the bomb into the test until the pressure falls 175 kPa from the maximum. Can the two 5 mL water additions be combined? No, they are located in the sample container and in the bomb body respectively. Can the precision be used as batch uncertainty? No. Can the original concentration conflict be unified on one's own? No; a decision requires reliable verification and controlled procedures.

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