ASTM WK95893
New Test Method for Condition Monitoring of Water in In-Service Petroleum and Hydrocarbon Based Lubricants by Trend Analysis Using Fourier Transform Infrared (FT-IR) Spectrometry1
1. Scope
This test method covers monitoring water in in-service petroleum and hydrocarbon based lubricants such as in diesel crankcase, motor, hydraulic, gear and compressor oils, as well as other types of lubricants that are prone to water ingress. This test method uses Fourier Transform Infrared (FT-IR) spectrometry for monitoring build-up of water in in-service petroleum and hydrocarbon based lubricants as a result of normal machinery operation. Petroleum and hydrocarbon based lubricants can incorporate water through a number of mechanisms including ingress, contamination, absorption etc . This test method is designed as a fast, simple spectroscopic check for monitoring of water in in-service petroleum and hydrocarbon based lubricants with the objective of helping diagnose the operational condition of the machine based on measuring the level of water in the oil. Acquisition of FT-IR spectral data for measuring water in in-service oil and lubricant samples is described in the ASTM D7418 Standard Practice. In this test method, measurement and data interpretation parameters for water using direct trend analysis are presented. This test method is based on trending of spectral changes associated with water of in-service petroleum and hydrocarbon based lubricants. Warnings or alarm limits can be set on the basis of a fixed minimum value for a single measurement or, alternatively, can be based on a rate of change of the response measured.Keywords
In-service lubricant analysis, water contamination, Fourier Transform Infrared (FTIR) Analysis, spectroscopy, Infrared (IR) AnalysisRationale
Currently, there are no standard test methods for the FT-IR condition monitoring of water in in-service oils and lubricants, although water has been measured by FT-IR spectrometry for some time as one of the parameters specified in Standard Practice E2412, “Standard Practice for Condition Monitoring of Used Lubricants by Trend Analysis using Fourier Transform Infrared (FT-IR) Spectrometry.” Standard Practice E2412 provides a generalized, multi-parameter protocol for condition monitoring of in-service petroleum and ester lubricants by FT-IR spectroscopy and details a variety of acceptable instrument settings as well as parameters for different lubricant types. However, for an inter-laboratory cross-check program, specific instrument settings should be defined since different cell window materials, apodizations, background collection techniques, etc. will result in variations in the final spectrum obtained. Therefore, ASTM Standard Practice, D 7418, created using Standard Practice E 2412 as a guide, details specific instrument settings and FT-IR spectral acquisition protocols for in-service condition monitoring. This test method describes the measurement of water in in-service oils and lubricants employing the FT-IR spectral data acquired according to the protocol specified in Standard Practice D 7418 for both direct trending and differential approaches.
Work Item Status
Date Initiated: 07-31-2025
Technical Contact: Keith Schomburg
Item: 000
Ballot:
Status: