ASTM D7959-24
Standard Test Method for Chloride Content Determination of Aviation Turbine Fuels using Chloride Test Strip

Standard No.

ASTM D7959-24

Release Date

2024

Published By

American Society for Testing and Materials (ASTM)  US  /  ASTM

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ASTM D7959-24

Introduction

Analysis of the Standard's Core Content

ASTM D7959-24 specifies a rapid method for determining the chloride content in aviation turbine fuel using chloride test strips. This method uses a magnetic stirrer and pH 7 buffer to extract chloride from the fuel, achieving a detection sensitivity of 0.0017 mg/L.

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Technical Principle and Process

Steps	Key Parameters	Equipment Requirements
Sample Preparation	3L fuel + 5mL buffer	4L beaker + cross stirring bar
Extraction Process	10 minutes of vigorous stirring	Magnetic stirring plate (no heating)
Detection and Analysis	Test strip reaction for 5 minutes	Hach Chloride QuanTab®

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Method Characteristics Comparison

Compared with the traditional potentiometric titration method, this method has the following advantages:

• Speed advantage: The whole process takes only 25 minutes (the traditional method takes 2 hours)
• Cost advantage: No expensive instruments are required
• Sensitivity limitation: Only ionic chloride is detected, not applicable to organochlorine compounds

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Key points for implementation of the standard

According to the IATA case study, fuel system corrosion often occurs when the chloride concentration is >0.1mg/L. Notes during implementation:

1. A blank control must be performed for each batch of buffer
2. The stirring speed must make the 5th line of the Distillate Fuel Bar Chart disappear
3. The test strip reading should be performed immediately after the yellow strip turns black

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Background of Technological Evolution

The 2015 edition first introduced the test strip method. The 2024 edition has major revisions:

• Added reference to D4175 terminology
• Clarified the requirements for stirrer shape (cross shape is better than bar shape)
• Updated the accuracy calculation formula: Repeatability = 0.2478(X+0.0001)^0.5432

ASTM D7959-24 history

• 2024 ASTM D7959-24 Standard Test Method for Chloride Content Determination of Aviation Turbine Fuels using Chloride Test Strip
• 2019 ASTM D7959-19 Standard Test Method for Chloride Content Determination of Aviation Turbine Fuels using Chloride Test Strip
• 2016 ASTM D7959-16 Standard Test Method for Chloride Content Determination of Aviation Turbine Fuels using Chloride Test Strip
• 2015 ASTM D7959-15 Standard Test Method for Chloride Content Determination

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