NB/SH/T 0917-2015 Determination of total volatile sulfur in gaseous hydrocarbons and liquefied petroleum gas — Ultraviolet fluorescence 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.

NB/SH/T 0917-2015 specifies the determination of total volatile sulfur in gaseous hydrocarbons and liquefied petroleum gas by oxidative combustion and ultraviolet fluorescence, and this page summarizes its verification boundary, scope, principle, apparatus, reagents, typical conditions, calibration, calculations, reporting and precision.

Evidence note: an original learning card compiled page by page from the 13-page 2015 original in hand, not the full standard text or a controlled operating procedure. Technical review is pending; the symbol connection in equation 4, the dimensions of the dilution factor in equation 6 and the clause number 15.2.3 are retained as queries, and the formulas on this page must not be taken directly as a verified calculation program. The figures and complete piping have not been reconstructed, and current status, equivalence or product applicability is not inferred.

Version studied and verification boundary: Original PDF pages 1–2; SAC/TC 2015 No. 12 filing announcement. The version studied is NB/SH/T 0917-2015, published 2015-10-27 and implemented 2016-03-01; the identity of the 13-page original agrees with filing number 52300-2015. The filing announcement verifies the year and the publication facts, and the standard is not called current today on the basis of the announcement alone. The original foreword states modification adoption of ASTM D6667-14, which cannot be called equivalence; the adoption relationship is recorded only as in the original of this edition. The original and the OCR are read-only, the OCR serves only for locating, and checking page counts and numbers is not technical review approval.

Scope and limits: Original PDF page 3, Chapter 1. Applies to total volatile sulfur in gaseous hydrocarbons and LPG as raw materials, intermediate products and final products. The precision-validated ranges are 1–100 mg/kg for gaseous hydrocarbons and 1–196 mg/kg for LPG; these are not detection limits or a universal range for any instrument. The halogen mass fraction of LPG must be less than 0.35%; non-volatile sulfur-containing compounds are not covered. The 200 mg/kg calibration point in the table must not erase the 196 validation upper bound. Specific test samples and products still require confirmation by evidence.

Principle and signal: Original PDF page 3, Chapters 3–4. A quantitative sample aliquot enters a high-temperature oxygen-rich combustion zone, sulfur is oxidized to SO2, and after dehydration it is excited by ultraviolet light and emits fluorescence again; a photomultiplier tube measures the response, which is converted to total sulfur after calibration. Sulfur loss, contamination, incomplete combustion and moisture can all affect the response; the fluorescence response is not an uncalibrated content, nor is it equal to a product certificate or a sample acceptance decision.

Apparatus and sample introduction: Original PDF pages 4–5, Chapter 5, Figures 1–4. The furnace temperature is 1075 ± 25 °C; the quartz combustion tube, flow control, selective dehydration, quantitative fluorescence detection and recording integration form the measurement chain. The carrier gas of about 30 mL/min carries the sample into the oxidation zone, and structural modifications must not reduce precision. The gas valve, liquid valve and universal valve/LTG structures differ: the gas sample loop is heated and temperature-controlled, the liquid has a sample loop and an expansion chamber, and the LTG vaporizes first. The watermark covers part of the details of the original figure, and manufacturing dimensions or the complete piping have not been reconstructed; conformity with this method is not confirmed by the instrument name.

Reagents, gases and standards: Original PDF page 6, Chapter 6, Table 1. The carrier gas helium or argon has a purity of >99.998% and water ≤5 mg/kg; oxygen is at least 99.75% with water ≤5 mg/kg, and the high-pressure and combustion-supporting risks must be retained. Reagents must be analytical grade or must not reduce accuracy. The original table gives examples of dimethyl sulfide in n-butane, isobutane, propylene and propane matrices; other sulfides must not reduce accuracy/precision, and no new product applicability relationship may be added on that basis. Standards are periodically re-prepared or re-quantified; the general 6–12 months is the statement of the original, not the expiry, supply or certificate commitment of a specific product. Sulfide example | Dilution matrix Dimethyl sulfide | n-butane Dimethyl sulfide | isobutane Dimethyl sulfide | propylene Dimethyl sulfide | propane

Safety, sampling and preparation: Original PDF pages 3, 6–7, Chapters 3, 7–9. Direct, reflected and scattered ultraviolet light can injure the eyes or body; high temperature, flammability and high pressure coexist, and the pressure resistance of containers/connectors must be verified. Sample according to GB/T 13609 or SH/T 0233, analyse as soon as possible to reduce sulfur loss and contamination, and mix thoroughly after storage. Install, stabilize and leak-test according to the manufacturer, and calibrate the baseline and blank. This is a learning summary, not authorization for hazardous operations or a complete controlled safety procedure. Undated original references are not automatically changed to the current edition.

Typical operating conditions of the original: Original PDF page 7, Table 2. The following are the typical conditions of the original table and do not replace confirmation on the actual instrument. The gas sample in mL and the LPG in μL are different, and the furnace oxygen/injection oxygen/injection carrier gas flows must not be merged into a total flow. Condition | Original value Injection system temperature/°C | 85±20 Carrier gas injection flow rate/(mL/min) | 25–30 Furnace temperature/°C | 1075±25 Furnace oxygen flow meter setting/(mL/min) | 375–450 Injection oxygen flow meter setting/(mL/min) | 10–30 Injection carrier gas flow meter setting/(mL/min) | 130–160 Gaseous sample injection volume/mL | 10–20 LPG sample injection volume/μL | 15

Calibration concentration matrix and response: Original PDF pages 7–8, Chapter 10, Table 3. Choose representative standards and diluents with concentrations covering the sample; wider concentrations may be used but the precision has not been determined. Blanks in the original table are not zero measurements, and dashes are not filled in with numbers. Use the same or similar injection volume and flush thoroughly; if the LPG contains bubbles, flush again; multi-point/single-point and blank correction are handled separately. For a single-point standard, the maximum difference from the sample sulfur content is ±25%, and the standard is run at least three times; performance is checked at least daily. Curve 1/(mg/kg) | Curve 2/(mg/kg) | Curve 3/(mg/kg) blank | blank | blank 5.00 | 10.00 | 50 10.00 | 50.00 | 100 — | 100.00 | 200

Sample analysis and quality records: Original PDF page 8, Chapter 11. Analyse each sample at least three times and report the average; the gas density should correspond to the detection temperature. If carbon deposition/incomplete combustion occurs, reduce the rate or injection volume and investigate the cause; after cleaning, check tightness and recalibrate. Keep records of samples, standards, temperature/density, injection volume, response and blank, calibration and QC. The mean of three analyses and the mean of two tests in the precision formula X are not the same definition.

Literal calculation and symbol queries in the original: Original PDF pages 8–9, Chapter 12, equations 1–7. Equation (1) S_m=(G×d)/s: G is the measured sulfur in mg/kg, d the density of the standard and s the density of the sample, both in g/mL. Equation (2) K=A_c/(M_c×S_cg); equation (3) K=A_c/(V_c×S_cv). K is the response per ng of sulfur, the standard mass concentration S_cg is in mg/kg and the volume concentration S_cv in mg/L. Equation (4) reads literally M_c=V×D_c, where M_c is the standard injection mass in mg and D_c the density of the standard at the detection temperature in g/mL; but the V that follows is defined as the sample injection volume in μL, while the standard volume is listed separately as V_c. This symbol connection query is not corrected to V_c on one's own initiative. Equation (5) S_0=A/(M×K×F_g), result in mg/kg; equation (6) S_0=A/(V×K×F_v), result in mg/L; equation (7) M=V×D, where M is the sample injection mass in mg, V in μL and D the density at the detection temperature in g/mL. F_g is sample mass/(sample mass + solvent mass), g/g. Although F_v is called the volume dilution factor, the original defines it as sample mass/(sample volume + solvent volume), g/mL; there is a dimensional query in connecting it with the mg/L result of equation 6, and it is retained literally rather than changed into a dimensionless volume fraction. These equations are not verified calculators that can be executed directly, and technical verification is required before use.

Reporting and rounding: Original PDF page 9, Chapter 13. Results of ≥10 mg/kg are rounded to 1 mg/kg, and results below 10 mg/kg to 0.1 mg/kg, with a statement that they were determined according to this standard. The number of decimal places is not a detection limit, quantification limit or instrument error. The mass/volume concentration units, density temperature, dilution and records verifying the original formula queries must be retained, and mg/L and mg/kg must not be mixed directly without density treatment.

Precision and typical values: Original PDF pages 9–10, Chapter 15, equations 8–11, Table 4. At the 95% confidence level: for gaseous hydrocarbons 1–100 mg/kg, r = 0.1152X, R = 0.3130X; for LPG 1–196 mg/kg, r = 0.2707X^0.7, R = 2.3205X^0.7. X is the arithmetic mean of two test results in mg/kg, and the formulas are not applied directly outside the range. The typical values of Table 4 are method precision, not product measurements; the dashes for 150/196 gaseous hydrocarbons are retained. The original typical value clause is numbered 15.2.3, between 15.1.2 and 15.2, and this numbering anomaly is explicitly retained. The original bias discussion provides no bias correction for this sample and does not promise absolute freedom from bias. Sulfur content | r gaseous hydrocarbons | r LPG | R gaseous hydrocarbons | R LPG 1 | 0.1 | 0.3 | 0.3 | 2.3 5 | 0.6 | 0.8 | 1.6 | 7.2 25 | 2.9 | 2.6 | 7.8 | 22 50 | 5.8 | 4.2 | 16 | 36 100 | 12 | 6.8 | 31 | 58 150 | — | 9 | — | 77 196 | — | 11 | — | 93

Informative annexes and safety boundaries: Original PDF pages 11–13, informative Annexes A/B/C. A.1–A.6 cover QC means/control ranges, control charts and investigation of out-of-control causes, with frequency depending on importance, stability and customer requirements; normally performed with routine samples on each test day. QC samples must be representative, homogeneous and stable, and a successful calibration alone must not be claimed as control. B.1–B.13 give typical responses of 20 s to 1 min, not a fixed integration time; a carrier gas of >30 mL/min may cause incomplete combustion. B.8 states that cylinders are usually >1.38 MPa to avoid bubbles; this must not be combined with the general C.4 value of <5.17 MPa and the system rating of 6.21 MPa or the device capability into a fixed universal pressure window. C.1–C.8 require checking the gas path, keeping exhaust away from ignition sources, monitoring bubbles and depressurizing/purging after the test. The text held ends at C.8; A/B/C are all informative; Figure B.1 is a typical curve, not an actual acceptance record. All piping, manufacturing drawings and controlled safety steps have not been reconstructed.

References, open items and independent acceptance: Original PDF pages 2–13; source evidence for this round. The original cites GB/T 11062, GB/T 13609, SH/T 0233, NB/SH/T 0843, ASTM D1070, ASTM MNL7 and others without years; the choice of cited version, current status, equivalence or specific product applicability is not decided for the user. Three original queries are retained: the V/V_c connection in equation 4, the definition of F_v against the dimensions of equation 6, and the 15.2.3 clause number; complete figures/piping, hazardous operations and real instrument calibration, technical review and independent Hermes/Grok acceptance remain to be completed. The old public product association block is retained verbatim, no relationship is added or modified, and the scanned original is not published.

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