1 Scope
This standard is applicable to determination of contents of barium, calcium, phosphorus, sulfur and zinc in lubricating oil and additive with element concentration scope of 0.03%(m/m)~1.0%(m/m)[0.01%(m/m)~2.0%(m/m) for sulfur]. The lubricating oil and additive with high element concentration may be determined after dilution.
2 Summary of Method
2.1 Calibration of measurement strength of analytic element with mathematical method may prevent from interference of other elements in the specimen and X ray fluorescence spectrum strength of all the elements shall be known in case of calibration with mathematical methods.
2.1.1 Place the specimen in X ray bundle and determine X-ray fluorescence intensity and background intensity of analytical line of barium, calcium, phosphorus, sulfur and zinc; the analytic element concentration is obtained by the measured net strength (analytical line intensity minus background intensity) and the correction factor obtained from the standard sample through calculation.
2.1.2 The inter-element correction factor may be calculated through regression analysis with a series of standard samples and the initial calibration is also carried out for X-ray fluorescence spectrometer.
2.1.3 The apparatus calibration may be finished with a small amount of specimen and only carried out when the inter-element correction factor needs to be re-determined. In case of lots of analysis, any of these specimens may monitor the drifting of the apparatus.
2.2 Specimens may be diluted with a diluent (white oil, coal oil and dimethylbenzene etc) in case of determination of additive or complex additive to make the analytic element concentration within the scope specified in Chapter 1.
3 Significance and Use
Some lubricating oils formulae contain the organometallic additive which plays an roles of detergent agent, oxidation inhibitor and antiwear additive etc. ; some additives contain one or more elements of barium, calcium, phosphorus, sulfur and zinc and this standard provides methods to determine the concentration of the five elements. The measured concentration provides data for the contents of additive in lubricating oil.
Contents
Foreword I
1 Scope
2 Summary of Method
3 Significance and Use
4 Interference
5 Apparatus
6 Reagents and Materials
7 Preparation of the Calibration Standard Sample
8 Calibration
9 Procedure
10 Precision and Bias
