ISO 8573-5:2001 pdf download

ISO 8573-5:2001 pdf download.Compressed air一 Part 5: Test methods for oil vapour and organic solvent content.
The temperature and velocity range shall be within the ranges specified by the manufacturer of the test equipment. See clause A.1 for the sampling procedure.
6.2 Extraction
The probe shall be installed in a small extraction tube, which conducts an air sample from the main pipe into the
measurement chamber, where the measurement shall be made under system pressure.
6.3 Sampling and measurement conditions
6.3.1 Repeatability
Depending on the repeatability of the method and the experience of the parties involved in the provision of
measurement facilities, a number of sequential measurements may need to be carried out.
6.3.2 Sampling system
Materials used for conducting the air in the sampling system shall not affect the oil vapour content of the sample. The sampling system pressure shall be recorded during measurement.
The sampling system temperature shall be higher than the prevailing dew-point and shall be recorded during measurement (see ISO 8573-3).
6.3.3 Measurement system
The compressed air system and sampling system shall have reached a steady state before any measurement is carried out and shall be kept steady during measurement. The readings from two consecutive measurements, having between them an interval of at least 20 minutes, may not differ by more than is implied by the accuracy of the measuring system.
6.3.4 Test equipment
The general arrangement of the test equipment for extracting a sample shall be as shown in Figure A.1. It is important that the test equipment not affect the collected sample.
Precautions shall be taken to ensure there is no temperature drop between the compressed air system and the collection point. Practical procedures as identified in ISO 8573-2 should also be considered.
7 Measurement
Consideration shall be given to the calibration requirements of the measurement equipment used, as described in applicable instructions, and to the degree of vapour concentration being measured.
The requirements on equipment handling, measurement and evaluation shall be according to Method B2 of
ISO 8573-2:1996.
See clause A.1 for specification of the gas chromatography test procedure.
Prepare for measurement by cleaning and degreasing the measuring and stainless steel tubes with a solvent that does not add to the overall hydrocarbon content of the sample. Before measuring, flush the sample point and the stainless steel tube up to the membrane filter with compressed air from the system, for example, for 5 mm.
Reference should be made to ISO 9486 and ISO 9487 with regard to methodology.
The value of such a deviation (normally 95 % confidence limit) constitutes a criterion of the accuracy of the particular measurement.
It is assumed that all systematic errors that may occur in the measurement of the individual quantities, and of the characteristics of the air, may be compensated for by corrections. A further assumption is that the confidence limits in errors in reading and integration errors may be negligible if the number of readings is sufficient.
The (small) systematic errors that may occur are covered by the inaccuracy of measurements.
Quality classifications and limits of error are often invoked for ascertaining the uncertainty of individual measurement because, apart from the exceptions (e.g. electrical transducers), they constitute only a fraction of the quality class or the limit of error.
The information about ascertaining the uncertainty of the measurement of the individual quantities measured and
on the confidence limits of the gas properties are approximations. These approximations can only be improved at a
disproportionate expense. See ISO 2602 and ISO 2854.
10 Test report
10.1 Statements
Statements of the oil vapour or organic solvent content in the compressed air, or both, shall only be used in conjunction with statements on oil aerosol content when made for classification purposes according to ISO 8573-1, and shall be made in such a manner that the values can be verified according to the procedures of the measurement methods specified in this part of ISO 8573.
Statements according to this part of ISO 8573 shall not be used to characterize oil content in air without mention that the total amount of oil is not considered.
10.2 Information
The test report used to declare oil vapour concentration according to this part of ISO 8573 shall contain the following information:
a) a description of the compressed air system and its working conditions, with sufficient detail to determine the applicability of the declared concentration value, including
— pressure, temperature, and
other contaminants;
b) a description of the sampling point at which the samples were taken;
c) a description of the sampling and measurement system used, in particular the materials used, and details of its calibration record;
d) the phrase “Declared content of oil vapour in mg/rn3 in accordance with ISO 8573-5”, followed by the figure for the actual, average measured value evaluated according to clause 8, calculated in respect of the reference conditions.