ASTM D5705 is the industry standard for measuring hydrogen sulfide ( cap H sub 2 cap S
) in the vapor phase (headspace) above residual fuel oils. Often used as a rapid field test, it helps refiners and fuel terminals manage safety risks and quality control without requiring complex laboratory instrumentation like gas chromatographs. Key Features of ASTM D5705 : Field determination of cap H sub 2 cap S in the equilibrium headspace of fuel oil. Measurement Range : Applicable from (micromoles per mole). Applicable Materials
: Residual fuel oils conforming to Specification D396 Grades 4, 5 (Heavy), and 6, with specific viscosity ranges (e.g., Health and Safety Focus
: Vapor-phase testing is primarily used for assessing exposure risks for personnel handling fuel storage and transport. Testing Procedure Summary
The method is designed for speed and consistency in field settings: Sample Collection
: A fresh sample is collected in a specialized glass container, typically filled halfway to allow for headspace breakout. Equilibrium Setup : The sample is heated (often to
) and agitated—sometimes using an orbital shaker—to release cap H sub 2 cap S into the vapor phase. Measurement
: A length-of-stain detector tube (e.g., lead acetate) is inserted into the headspace.
: An air sampling pump draws the vapor through the tube; the resulting color change indicates the concentration in parts per million (ppm). Limitations & Complementary Methods
While ASTM D5705 is excellent for a "moment-in-time" safety check, it has specific limitations:
Understanding ASTM D5705: A Guide to Hydrogen Sulfide Testing in Residual Fuel Oils
In the world of petroleum and heavy fuels, safety and precision are paramount. One of the most critical factors to manage is the presence of Hydrogen Sulfide ( cap H sub 2 cap S
)—a colorless, highly toxic, and corrosive gas. For industry professionals, ASTM D5705 is the standard field method used to measure cap H sub 2 cap S in the vapor phase above residual fuel oils. What is ASTM D5705?
ASTM D5705 is a standard test method specifically designed for the field determination cap H sub 2 cap S
in the equilibrium headspace of a fuel sample. Unlike lab-intensive methods that might require complex gas chromatography, D5705 provides a rapid, consistent way for refineries and fuel terminals to assess safety risks on-site. Key Scope and Applicability Target Materials : It applies to residual fuel oils like Specification Grade Nos. 4, 5 (Heavy), and 6. Viscosity Range : Applicable to liquids with a viscosity between 5.5 40 raised to the composed with power cap C 100 raised to the composed with power cap C Measurement Range : The test covers concentrations from 5 to 4000 ppm v/v (parts per million by volume). How the Test Works
The procedure is designed to simulate an "equilibrium headspace," meaning the vapor space is in balance with the liquid. Preparation : A 1-liter cap H sub 2 cap S
-inert glass bottle is filled to 50% capacity with the fuel sample. : The container is heated to 60 raised to the composed with power cap C
and agitated on an orbital shaker at 220 rpm for three minutes to release the gas into the headspace. Measurement length-of-stain detector tube and a hand-operated pump are used to measure the cap H sub 2 cap S concentration in the vapor space. Why Does It Matter? Safety First cap H sub 2 cap S
is a potent chemical asphyxiant. At concentrations above 100 ppm, it can paralyze the olfactory nerves, making it impossible to smell the "rotten egg" odor that normally warns of its presence. Consistent Benchmarking
: While this test doesn't perfectly simulate the exact conditions inside a massive storage tank, it provides a consistent level of measurement that is independent of the operator or location. Regulatory Compliance : Many terminals and transport vessels require an ASTM D5705 "Can Test" before they will accept a product for discharge. Vapor vs. Liquid Phase Testing It is important to distinguish between vapor phase (ASTM D5705) and liquid phase testing (such as ASTM D7621 ASTM D6021 Vapor phase results (D5705) are primarily used for health and safety assessments of the immediate atmosphere. Liquid phase results are used for product quality control
and understanding the "propensity" of a fuel to release hazardous gases over time.
For those looking for the full technical details, you can find the official ASTM D5705-20 standard directly on the ASTM International website methods like IP 570?
Purpose: This field determination method measures hydrogen sulfide (
) concentration in the equilibrium headspace (vapor phase) above residual fuel oils. Significance:
is highly toxic; even low concentrations (e.g., 10 ppm) can cause serious health risks. This test helps determine if
levels in storage tank headspaces are hazardous before opening or loading tanks. Applicability:
Fuel Types: Specifically applicable to liquids with viscosities ranging from 5.5 at 40°C to 50
at 100°C, conforming to ASTM D396 Grade Nos. 4, 5 (Heavy), and 6. Range: The test covers concentrations from 5 to 4000 (5 ppm v/v to 4000 ppm v/v). Method Summary Sample Collection: A 1-liter
-inert glass test bottle is filled to 50% capacity with the fuel oil sample.
Equilibrium Generation: The bottle is agitated (shaken) to allow
in the liquid phase to reach equilibrium with the vapor phase in the headspace.
Measurement: A lead acetate gas detection tube is inserted into the vapor space (close to but not touching the liquid) to measure the concentration based on the length of the stain on the tube. Limitations Phase Focus: It strictly measures vapor-phase . It does not quantify the actual level in the liquid phase, which can be much higher.
Accuracy: Staining of the tubes can sometimes lead to misinterpretation of results, making it less precise than laboratory methods like ASTM D7621 for liquid-phase analysis. Latest Revisions
Subject: ASTM D5705 PDF – Standard Test Method for Measurement of Hydrogen Sulfide in Natural Gas
Overview ASTM D5705 is a critical standard used in the natural gas industry for the rapid, on-site measurement of hydrogen sulfide (H₂S) content. This method employs a color indicator tube (often referred to as a “length-of-stain” tube) to determine H₂S concentrations ranging from approximately 0.5 to 100 ppm by volume. It is widely adopted for field quality control, pipeline integrity monitoring, and regulatory compliance because it requires no laboratory equipment or complex sample conditioning.
Why You Need This Standard
- Fast, Field-Ready Testing: Obtain results in under 5 minutes without transporting gas samples to a lab.
- Safety & Corrosion Control: Accurately detect H₂S levels to prevent metal embrittlement (sulfide stress cracking) in pipelines and processing equipment.
- Compliance: Meet contractual and environmental limits for H₂S in fuel gas, natural gas streams, and process gases.
- Rugged Simplicity: The method uses a hand-operated pump and sealed glass tubes—ideal for remote wellheads, compressor stations, or LNG facilities.
What’s Inside the Official ASTM D5705 PDF
- Step-by-Step Procedure: Detailed instructions for sample connection, tube selection, stroke count, and stain reading.
- Interferences & Limitations: Notes on how other acidic gases (e.g., mercaptans, CO₂) may affect accuracy, and temperature/pressure correction factors.
- Precision & Bias: Statistical data on repeatability and reproducibility across different labs and field conditions.
- Apparatus Requirements: Specifications for the manual pump, colorimetric tubes (proprietary to various manufacturers), and sample line materials.
Who Should Download the PDF
- Natural gas pipeline operators and field technicians
- Gas quality analysts and environmental compliance officers
- H₂S scavenger system vendors
- Laboratories running comparative gas chromatography (GC) validation
- Engineering firms designing gas treatment units
Important Notes Before Downloading
- The official ASTM D5705 PDF is copyright protected and must be purchased from ASTM International (Item No. D5705-20, current active version as of this writing). Be cautious of free “pirated” PDFs—they often contain obsolete methods, missing tables, or incorrect correction factors.
- Always confirm you have the latest version (e.g., D5705-20) because earlier editions may reference outdated tube designs or pressure correction formulas.
- The method is not equivalent to GC or lead acetate tape methods; it serves as a rapid screening test, not a referee method for high-accuracy custody transfer.
Where to Get the Authorized ASTM D5705 PDF
Purchase directly from the ASTM Compass Store (www.astm.org) or authorized resellers (IHS Markit, Techstreet, ANSI). Redistribution of paid PDFs violates copyright law; use a single-user license for your internal quality system.
Alternatives to Consider If you require continuous online monitoring or ultra-low H₂S detection (<0.1 ppm), consider:
- ASTM D4810 (lead acetate tape method)
- ASTM D5504 (GC with sulfur chemiluminescence detection)
Need a specific section of the write-up expanded (e.g., step-by-step test summary, price / page count info, or comparison to other methods)? Let me know.
ASTM D5705, often called the "Can Test," is the industry standard for measuring hydrogen sulfide (H₂S) in the vapor phase above residual fuel oils. This method is utilized for field-portable, rapid assessments of H₂S levels ranging from 5 ppm to 4000 ppm, essential for safety in marine transport and terminal storage. Read the full technical standard details via the ASTM D5705-2015 PDF.
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ASTM D5705 is a standard test method developed by the American Society for Testing and Materials (ASTM) that covers the determination of the pour point of petroleum products.
Here's a helpful review:
What is ASTM D5705?
ASTM D5705 is a standard test method that outlines the procedure for determining the pour point of petroleum products, such as fuels, lubricants, and other petroleum-based products. The pour point is the lowest temperature at which a petroleum product will flow when cooled.
Key aspects of ASTM D5705:
- Scope: This standard applies to petroleum products with a pour point between -60°C and 20°C (-76°F and 68°F).
- Apparatus: The test requires a pour point apparatus, which consists of a sample container, a thermometer, and a cooling bath.
- Procedure: The test involves cooling the sample in a controlled manner, then observing the sample for flow characteristics at specific temperatures.
- Interpretation: The pour point is determined by observing the temperature at which the sample no longer flows.
Importance of ASTM D5705:
- Fuel performance: The pour point is an essential parameter in evaluating the cold-flow properties of fuels, particularly in cold climates.
- Lubricant performance: For lubricants, the pour point affects their ability to flow and lubricate equipment at low temperatures.
- Product development: ASTM D5705 helps in the development of new petroleum products with improved cold-flow properties.
Review of the PDF:
The ASTM D5705 PDF provides a detailed description of the test method, including:
- Clear instructions: The document offers clear, step-by-step instructions for conducting the test.
- Precise definitions: The standard provides precise definitions of terms and apparatus used in the test.
- Reproducibility: The document includes data on the reproducibility of the test method.
Overall review:
The ASTM D5705 PDF is a comprehensive and well-structured document that provides a clear outline of the test method for determining the pour point of petroleum products. The standard is essential for anyone working with petroleum products, particularly in the fuel and lubricant industries. With its clear instructions and precise definitions, this document helps ensure accurate and reliable results.
The ASTM D5705 standard establishes a protocol for the field determination of hydrogen sulfide ( cap H sub 2 cap S
in the vapor phase above residual fuel oils. Below is a report summary based on the D5705-20 Standard Test Report: ASTM D5705 1. Objective & Scope : To provide a rapid, consistent field method for measuring cap H sub 2 cap S
concentration in the equilibrium headspace of a fuel sample. Applicability : Residual fuel oils with a viscosity of 40 raised to the composed with power C 100 raised to the composed with power C Grade Nos. 4, 5 heavy, and 6). Detection Range ASTM International 2. Methodology Summary Preparation cap H sub 2 cap S
-inert glass test bottle is filled to 50% volume with the fuel sample.
: The vapor space above the sample is purged with nitrogen to displace air. Conditions : The sample is heated to
in an oven or water bath and agitated on an orbital shaker at for 3 minutes. Measurement
: A "length of stain" detector tube and a hand-operated pump are used to draw a vapor sample and measure the cap H sub 2 cap S concentration. iTeh Standards 3. Required Report Elements A standard report for this method typically includes: Sample Identity : Type of fuel, source, and batch information. Test Results : Concentration of cap H sub 2 cap S Instrument Details
: Brand and model of the detector tube and pump (they must be from the same manufacturer for accuracy). Procedural Notes : Any deviations from the standard temperature ( 60 raised to the composed with power C ) or agitation time. ASTM International 4. Significance & Safety cap H sub 2 cap S
is highly toxic; this test is critical for health and safety assessments at refineries and terminals. Limitations
: This field test measures vapor phase concentration at a specific moment and does not directly correlate to cap H sub 2 cap S levels in the liquid phase (refer to ASTM D7621 for liquid phase testing). ASTM International
For professional results, you can use specialized software like the GO Create Pro APP to ensure transparency and consistency in your reporting. ASTM D7621
regarding their effectiveness for liquid versus vapor phase testing? Astm D5705 Pdf
Understanding ASTM D5705: Standard Test Methods for Measuring the Uniaxial Tensile Properties of Ultra-High Molecular Weight Polyethylene (UHMWPE) Fibers
Introduction
Ultra-High Molecular Weight Polyethylene (UHMWPE) fibers are a type of high-performance material known for their exceptional strength, stiffness, and resistance to impact and chemicals. These fibers are widely used in various industries, including aerospace, defense, sports equipment, and medical devices. To ensure the quality and reliability of UHMWPE fibers, it's essential to test their mechanical properties, particularly their uniaxial tensile properties. This is where ASTM D5705 comes into play.
What is ASTM D5705?
ASTM D5705 is a standard test method developed by the American Society for Testing and Materials (ASTM) that provides a procedure for measuring the uniaxial tensile properties of UHMWPE fibers. The test method is specifically designed to evaluate the tensile strength, modulus, and strain at break of UHMWPE fibers.
Scope and Significance
The scope of ASTM D5705 includes the determination of the following properties:
- Tensile strength: The maximum stress a fiber can withstand without failing.
- Tensile modulus: The measure of a fiber's stiffness or resistance to deformation under tensile stress.
- Strain at break: The percentage of deformation at which a fiber fails.
These properties are critical in understanding the behavior of UHMWPE fibers under tensile loading, which is essential for designing and developing products that utilize these fibers.
Test Procedure
The test procedure outlined in ASTM D5705 involves the following steps:
- Sample preparation: UHMWPE fibers are prepared by cutting them to a specified gauge length and conditioning them at a controlled temperature and humidity.
- Testing: The fibers are then subjected to a uniaxial tensile test using a testing machine, which applies a gradually increasing load until the fiber fails.
- Data acquisition: The load and displacement data are recorded during the test, and the tensile strength, modulus, and strain at break are calculated.
Requirements and Recommendations
ASTM D5705 provides detailed requirements and recommendations for testing UHMWPE fibers, including:
- Testing machine: The testing machine should be capable of applying a constant rate of loading and measuring the load and displacement accurately.
- Fiber conditioning: Fibers should be conditioned at a controlled temperature and humidity to ensure stable test results.
- Gauge length: The gauge length of the fiber should be accurately measured to ensure accurate calculation of strain.
Conclusion
ASTM D5705 is a widely accepted standard test method for evaluating the uniaxial tensile properties of UHMWPE fibers. By following this test method, manufacturers, researchers, and users of UHMWPE fibers can ensure that their products meet the required performance standards. The test results obtained from ASTM D5705 can be used to design and develop innovative products that take advantage of the exceptional properties of UHMWPE fibers.
If you are interested in getting the ASTM D5705 PDF, you can visit the ASTM website (www.astm.org) or search for it on online libraries and databases that provide access to ASTM standards.
Would you like to add or change any information related to ASTM D5705? I'll be glad to update it!
How to Verify You Have the Right Version
Before you download any astm d5705 pdf, check the "REDLINE" or "Designation" date. The current designation follows the format: D5705 – 20 (meaning 2020 version) or D5705 – 22.
Always confirm with the ASTM website that your copy matches the most recent active version. Using a "withdrawn" standard is invalid for ISO 9001 or AS9100 audits.
The Core Goal
Unsaturated polyester resins (UPR) are used extensively in fiberglass-reinforced plastics, boat hulls, countertops, automotive parts, and construction materials. Styrene is a critical component—it acts as a cross-linking agent and a viscosity reducer. However, during manufacturing, not all styrene reacts. Residual styrene left in the final product can cause:
- Health hazards (volatile organic compound emissions)
- Odor issues in finished goods
- Long-term shrinkage or material weakness
ASTM D5705 provides a precise, repeatable method to measure exactly how much unreacted styrene remains in a liquid resin sample.
Conclusion: Why You Need the Official ASTM D5705 PDF
Searching for "ASTM D5705 PDF" is the first step toward ensuring your polyethylene packaging is safe, consumer-friendly, and compliant. The official PDF is not just a document—it is a quality tool that provides:
- A legally defensible test method
- Reproducible results accepted worldwide
- The latest precision data and updates
- Clear instructions to train your odor panel
Do not rely on third-party summaries or outdated free downloads. Purchase the current ASTM D5705-20 directly from ASTM International or an authorized reseller. Implement it in your quality system, and you will drastically reduce the risk of off-odor complaints, rejected shipments, and brand damage.
Last updated: October 2023. ASTM D5705 is a registered trademark of ASTM International. This article is for informational purposes and does not replace the official standard.
Title: An Overview of ASTM D5705: Standard Test Method for Measurement of Hydrogen Sulfide in the Headspace of Crude Oil
Introduction ASTM D5705 is a standard test method developed by ASTM International. It is specifically designed to quantify the concentration of hydrogen sulfide (H₂S) in the vapor phase (headspace) of crude oil samples. As H₂S is a highly toxic and corrosive gas, accurate measurement is critical for refining, transportation safety, and regulatory compliance. While the full standard is available as a PDF purchase from ASTM, this informative text summarizes the scope, procedure, and significance of the method.
1. Scope and Application The primary purpose of ASTM D5705 is to determine the vapor phase concentration of hydrogen sulfide (H₂S) in crude oil. This is distinct from measuring total sulfur content; this test specifically looks at the dangerous gas that accumulates in the air space above the liquid oil.
- Typical Range: The method is generally applicable for measuring H₂S concentrations ranging from 0.01 mg/L to 100 mg/L in the headspace.
- Relevance: It is widely used in the petroleum industry to assess the "sourness" of crude oil. High H₂S levels require specific handling protocols, material selection (to prevent corrosion), and safety measures for personnel.
2. Significance and Use
- Safety: H₂S is lethal at high concentrations. Knowing the headspace concentration helps facilities determine the Personal Protective Equipment (PPE) required for workers opening tanks or sampling.
- Corrosion Prevention: H₂S causes sulfide stress cracking and corrosion in pipelines and storage tanks. Refineries often set strict limits on H₂S content in crude oil received.
- Regulatory Compliance: The data helps companies comply with occupational safety regulations (such as OSHA) and environmental standards regarding emissions.
3. Summary of the Test Method The procedure involves creating a controlled equilibrium between the liquid crude oil and the gas above it, followed by chemical detection.
- Sample Preparation: A representative sample of crude oil is placed in a specialized container. It is vital that the sample is not agitated excessively, as this can artificially inflate H₂S readings.
- Headspace Development: The container is typically shaken or rotated to allow the liquid and gas phases to reach equilibrium at a controlled temperature.
- Measurement (Detector Tube Method): The most common procedure described in earlier versions of the standard involves drawing a specific volume of the headspace gas through a glass detector tube. These tubes contain a chemical reagent that changes color in the presence of H₂S. The length of the color stain corresponds to the concentration.
- Alternative Instrumentation: Modern applications often utilize portable gas chromatography or electronic H₂S analyzers for higher precision, though the chemical tube method remains the standard reference for field operations.
4. Interferences and Limitations When reviewing the ASTM D5705 PDF, users will find specific sections on interferences.
- Other Sulfur Compounds: Other sulfur species (like mercaptans) may interfere with the chemical reaction in detector tubes, potentially leading to inaccurate readings.
- Temperature: H₂S solubility in crude oil is temperature-dependent. The standard specifies strict temperature controls because readings can fluctuate significantly if the oil is hot versus cold.
- Vapor Pressure: Crude oils with very high vapor pressures may present challenges during sampling, potentially forcing gas out of the cylinder before analysis.
5. The Importance of the ASTM D5705 PDF The official PDF document is essential for laboratory personnel because it provides:
- Precise Dimensions: Detailed specifications for the sample cylinders and valving required to ensure safety and accuracy.
- Calculation Formulas: Exact equations to convert detector tube readings into standardized concentration units.
- Precision and Bias: Statistical data regarding the repeatability and reproducibility of the test results, which helps labs determine if their results are within acceptable margins of error.
Conclusion ASTM D5705 serves as a critical benchmark in the petroleum industry for managing the risks associated with hydrogen sulfide. While it provides a standardized "recipe" for analysis, its greatest value lies in enabling safe handling practices for crude oil transport and refining. Professionals using this method should always refer to the latest official version of the standard to ensure compliance with current safety and precision requirements.
ASTM D5705 is the Standard Test Method for Measurement of Hydrogen Sulfide ( H2Scap H sub 2 cap S
) in the Vapor Phase Above Residual Fuel Oils. It is a field determination method used primarily for safety and quality control to identify hazardous H2Scap H sub 2 cap S levels in the headspace of storage tanks or containers. Core Method Details Purpose: Measures H2Scap H sub 2 cap S
concentration in the equilibrium headspace (vapor phase) rather than the liquid phase.
Applicability: Designed for residual fuel oils (ASTM D396 Grade Nos. 4, 5 Heavy, and 6) with viscosities between 5.5 at 40°C and 50 at 100°C.
Typical Range: Measures vapor-phase concentrations from approximately 5 to 4000 ppm H2Scap H sub 2 cap S Procedural Overview
The test, often called the "Can Test," involves specific steps to create an equilibrium between the liquid fuel and the vapor: Preparation: A 1-liter H2Scap H sub 2 cap S
-inert glass test bottle is filled 50% with the fuel oil sample.
Agitation & Heating: The sample is heated and shaken as described in the standard to generate a representative vapor headspace.
Measurement: A lead acetate-filled gas detection tube (e.g., a Draeger tube) is used to measure the gas concentration in the vapor space. Limitations and Alternatives
Precision: This method is effective for identifying the presence of H2Scap H sub 2 cap S
but is considered less precise for exact quantification. Staining of the detection tubes can sometimes lead to misinterpretation. Related Standards:
ASTM D7621: Uses rapid liquid phase extraction for more precise liquid-phase H2Scap H sub 2 cap S determination.
ASTM D6021: Involves multiple headspace extraction and sulfur-specific detection. Official Resources
The full standard is a copyrighted document and must be purchased for complete procedural steps, safety requirements, and precision data:
Limitations and considerations
- Specimen history: molding method, crystallinity, fillers, and additives greatly affect results — always compare like‑for‑like.
- Test water purity and temperature: must be controlled; salts or elevated temperatures can accelerate absorption.
- Not a substitute for in‑service testing: D5705 gives controlled comparative data, but actual service environments (cycles, contaminants, pressure) may require additional testing.
- Alternative standards: other ASTM methods or ISO standards may be used for different specimen geometries, gases, or environmental exposures.
5. Summary
ASTM D5705 is a critical safety standard for the marine and power generation industries. It provides a reliable method for detecting dangerous levels of hydrogen sulfide in fuel oil storage tanks.
While the convenience of a PDF is undeniable, professionals are advised to purchase the document from ASTM or authorized distributors to ensure they have the most current, accurate, and legally compliant version of the test method.
ASTM D5705 is the standard test method for measuring hydrogen sulfide ( H2Scap H sub 2 cap S
) in the vapor phase (headspace) above residual fuel oils. This test is critical for safety and regulatory compliance in the maritime and petroleum industries. 1. Abstract
The ASTM D5705 test method provides a standardized procedure for determining the concentration of hydrogen sulfide in the vapor space of a closed container containing residual fuel oil. Given that H2Scap H sub 2 cap S
is a highly toxic and corrosive gas, accurate measurement is essential for assessing worker exposure risks and the integrity of storage and transport systems. This paper explores the methodology, chemical principles, and practical implications of the D5705 standard. 2. Technical Scope and Application
The standard is specifically designed for residual fuel oils, which are heavy fractions produced during the refining process. These oils often contain sulfur compounds that can decompose or react to release H2Scap H sub 2 cap S
gas into the headspace of storage tanks or tanker compartments. Measurement Range: The method typically covers H2Scap H sub 2 cap S concentrations from 5 to 4000 $\mu$mol/mol (ppm v/v). Temperature Sensitivity: Vapor phase H2Scap H sub 2 cap S
concentration is highly dependent on temperature; the standard dictates testing at ) to simulate common storage conditions. 3. Testing Methodology
The procedure utilizes a rapid, field-portable technique involving length-of-stain detector tubes.
Sample Collection: A representative sample of the fuel oil is collected in a specialized one-liter glass container, filling it to 50% of its capacity. Equilibration: The container is heated in a water bath to and agitated to ensure the H2Scap H sub 2 cap S reaches equilibrium between the liquid and vapor phases.
Measurement: A calibrated hand pump is used to draw a specific volume of the headspace vapor through a detector tube.
Reaction: The tube contains a chemical reagent (often lead acetate) that reacts with H2Scap H sub 2 cap S
, causing a visible color change. The length of the stained area corresponds to the gas concentration. 4. Chemical Principles
The detection relies on a simple yet effective precipitation reaction. When H2Scap H sub 2 cap S passes through lead acetate ( ) impregnated in the tube, it forms lead sulfide ( PbScap P b cap S ), which is black or brown:
H2S(g)+Pb(CH3COO)2(s)→PbS(s)+2CH3COOH(g)cap H sub 2 cap S open paren g close paren plus cap P b open paren cap C cap H sub 3 cap C cap O cap O close paren sub 2 open paren s close paren right arrow cap P b cap S open paren s close paren plus 2 cap C cap H sub 3 cap C cap O cap O cap H open paren g close paren
The precision of this measurement depends on the "Henry’s Law" relationship, where the amount of dissolved gas in the liquid is proportional to its partial pressure in the gas phase above it. 5. Significance and Safety Health Hazards: H2Scap H sub 2 cap S
is lethal at high concentrations and can cause "olfactory fatigue," where a person loses the ability to smell the gas before reaching dangerous levels. Corrosion Control: High H2Scap H sub 2 cap S
levels indicate a potential for "sour" conditions, which can lead to stress corrosion cracking in steel tanks.
Regulatory Compliance: Organizations like the International Maritime Organization (IMO) use D5705 data to set safety limits for fuel handling. 6. Limitations
While D5705 is excellent for rapid field assessment, it is a "snapshot" measurement. It does not account for the total H2Scap H sub 2 cap S
that might eventually evolve from the oil over long-term storage or during intense heating. For a more comprehensive liquid-phase analysis, ASTM D7621 is often used in conjunction.
Version Control
ASTM updates standards regularly. The current active version of D5705 might have been revised last year. A pirated PDF from 2012 will lack critical updates to GC column specifications or calibration procedures. Using an obsolete method could ruin a production batch.