ASTM D7624-22 PDF

Full title and description

Standard Test Method for Condition Monitoring of Nitration in In-Service Petroleum and Hydrocarbon-Based Lubricants by Trend Analysis Using Fourier Transform Infrared (FT-IR) Spectrometry (ASTM D7624‑22). This test method defines procedures for monitoring nitration by‑products in in‑service lubricants and engine oils using FT‑IR spectrometry and trend analysis (direct and differential approaches) to support condition monitoring and oil analysis programs.

Abstract

ASTM D7624‑22 describes FT‑IR‑based spectral measurement procedures and reporting conventions for tracking nitration levels in petroleum and hydrocarbon‑based lubricants in service. The method supports both direct trend and differential (baseline corrected) trend analyses, establishes units and reporting formats for absorbance‑based measurements, and is intended for routine oil condition monitoring to detect accumulation of nitration products that can affect lubricant performance and machine health. A precision statement for the method was developed from an interlaboratory study.

General information

• Status: Active / current designation D7624‑22.
• Publication date: 2022 (designation suffix: ‑22; published January 2022).
• Publisher: ASTM International.
• ICS / categories: 75.100 (Lubricants, industrial oils and related products); 75.160.20 (Liquid fuels).
• Edition / version: D7624‑22 (current edition, 2022).
• Number of pages: 5 pages.

Scope

This test method covers monitoring nitration in gasoline and natural‑gas engine oils and in other hydrocarbon‑based lubricants where nitration by‑products may form (for example via combustion or nitrosative chemistry). It specifies FT‑IR spectral measurement approaches and trend analysis procedures for routine condition monitoring rather than absolute compositional quantification. The standard includes guidance on units, pathlength conventions, and typical decision‑making uses of trend data.

Key topics and requirements

• Use of Fourier Transform Infrared (FT‑IR) spectrometry for monitoring nitration products in in‑service lubricants.
• Trend analysis approaches: direct trend analysis and differential (baseline‑corrected) trend analysis for time‑series monitoring.
• Reporting units and pathlength conventions (for example absorbance units scaled per pathlength—direct reporting conventions are specified in the method).
• Procedural requirements for sample handling, spectral collection, and data recording suitable for routine oil condition monitoring.
• Precision/validation information derived from an interlaboratory study and an associated ASTM research report.

Typical use and users

Used by oil analysis laboratories, reliability and condition‑monitoring teams, maintenance engineers, fleet operators, engine test laboratories, and instrument manufacturers producing FT‑IR oil analyzers. Typical applications include in‑service oil surveillance programs, root‑cause investigations where nitration is suspected, and baseline/trend programs for predictive maintenance.

Related standards

Standards commonly referenced alongside D7624 include other FT‑IR and oil condition monitoring practices and test methods such as ASTM D7418 (practice for FT‑IR spectrometer setup for oil monitoring), ASTM D7214 (used lubricant oxidation by FT‑IR), ASTM D7686 (field‑based soot monitoring), and ASTM E2412 (practice for condition monitoring by FT‑IR). Users often implement D7624 within a broader oil analysis program that references multiple petroleum/lubricant test methods.

Keywords

nitration; FT‑IR; Fourier Transform Infrared spectrometry; oil condition monitoring; in‑service lubricants; trend analysis; direct trend; differential trend; lubricant nitration; oil analysis.

FAQ

Q: What is this standard?

A: ASTM D7624‑22 is a standard test method specifying FT‑IR spectrometric procedures and trend‑analysis approaches for monitoring nitration in in‑service petroleum and hydrocarbon‑based lubricants.

Q: What does it cover?

A: It covers spectral measurement and reporting procedures for tracking nitration by‑products in engine oils and other lubricants using direct and differential FT‑IR trend analysis; it is intended for routine condition monitoring rather than compositional quantification.

Q: Who typically uses it?

A: Oil analysis laboratories, reliability engineers, maintenance teams, fleet and engine test laboratories, and FT‑IR instrument vendors involved in lubricant condition monitoring and predictive maintenance programs.

Q: Is it current or superseded?

A: The designation D7624‑22 represents the 2022 edition and is the current ASTM designation (active) for this test method. An interlaboratory precision statement and supporting research report accompany the method.

Q: Is it part of a series?

A: D7624 is part of a family of ASTM petroleum and lubricant standards addressing oil condition monitoring and FT‑IR techniques; it is used alongside related ASTM test methods and practices for oxidation, soot, spectrometer setup, and general condition‑monitoring practices.

Q: What are the key keywords?

A: Nitration; FT‑IR; trend analysis; lubricant condition monitoring; in‑service oil; oil analysis; absorbance; direct trend; differential trend.