ISO 8573-5 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 ctause A.1 for the samphng procedure.
6.2 Extraction
The probe shal 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 shal be recorded during measurement
The sampling system temperature shall be higher than the prevailing dew-point and shell 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 vapotr concentration being measured.
The requirements on equipment handling, measurement and evaluation shall be according to Method B2 of
ISO 8573-2:1996.
See ctause 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 min
Reference should be made to ISO 9486 and ISO 9487 with regard to methodology.
A.1.3 Determination
Analyse the main zone and the back-up zone separately, together with a Thlind-lest, using the following procedure
a) Extract the main zone and the back-up zone using carton distiphide. Use benzene-d6, toluene-d8. ethØbenzene-dlO and octane-d18 as intemal standards.
b) Extract the sorbent sample tube for 30 mm on a shaker.
c) Analyse the extract using a gas chromatograph with mass-spectroscop.c detection In full scan mode, analysing both blind tests and standards in the same way.
d) Identify dominant single ccwnponents as far as possible. Characterize, sum and calculate other single components (e.g. aliphatic and aromatic compounds) semi-quantitatively as toluene.
The detection limits shall be 0,1 pg to 0,5 pg per tube.
AlA Calculation
The principles given in ISO 8573-2 regarding analytical methods and retated calculations should be applied.
A.2 Chemical indicator tubes
For the purposes of this part of ISO 8573, detector tubes may be employed to provide an initial indication of the presence of oil vapour. Once identified, the gas chromatography method according to clause A.l shall be used to identify the quantitative aspect of the oil vapour present in the compressed air
For detailed information regarding the application of detector tubes refer to the manufacturer’s literature.
ISO 8573-5 pdf download – Compressed air一 Part 5: Test methods for oil vapour and organic solvent content
