1、Designation: F 327 08Standard Practice forSampling Gas Blow Down Systems and Components forParticulate Contamination by Automatic Particle MonitorMethod1This standard is issued under the fixed designation F 327; the number immediately following the designation indicates the year oforiginal adoption
2、or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice describes how to connect, prepare, andsample pressurized gas sy
3、stems (having up to 19.1-mm (0.75-in.) diameter lines) for particulate contamination by using anautomatic monitor.1.2 The values stated in MKS units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafe
4、ty concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For hazard state-ments, see Section 5.2. Terminology2.1 Definitions:2.1.1
5、downstream terminal pointthe point in a gas systemfrom which gas is fed into a further system or component,usually the designated “sample port.”2.1.2 filtered gas systema gas system that is equippedwith required filtration devices to furnish gas that is suitablyclean for the intended application.2.1
6、.3 purgeto flush a gas supply system or componentwith a regulated flow of gas.2.1.4 sample portthe designated point in a gas system orcomponent from which a representative gas sample may betaken.3. Summary of Practice3.1 The pressurized gas system or component and theapparatus are prepared in accord
7、ance with the requirements ofthe users sample analysis procedure. The sensing unit of theautomatic particle monitor is connected to the designatedsample port which is under purge condition. The systemflow-rate is adjusted to the sample flow rate requirement. Allthe gas passing through the sensing un
8、it is monitored forparticulate contamination until the required sample volume hasbeen analyzed.4. Apparatus4.1 Automatic Monitor, with sensor that sizes and counts allentering fluid in accordance with the users requirements forpressure, flow, temperature, and accuracy.4.2 Filtered Gas SystemSee Fig.
9、 1.4.3 Stop Watch or Timer, with a + 1, 0-s resolution.4.4 Miscellaneous Fittings, as needed for sampling pointadaption, cleaned and packaged within system contaminationrequirements.4.5 Connecting Lines, cleaned and packaged within systemcontamination requirements.4.6 Flowmeter, calibrated for the s
10、ample port fluid, flow,and temperature requirements.5. Hazards5.1 Personnel must stand clear of exiting gas.5.2 Ear protection must be used when gas flow approachessonic velocity.5.3 All lines and associated system components must beconnected and operated within the requirements of recognizedsafety
11、codes.6. Procedure6.1 Establish a minimum continuous purge pressure of 6.89kPa (1 psig) gage or 2.83 dm3/min (0.1 ft3/min), flow from thefiltered gas pressure supply.6.2 Connect one end of a suitable connecting line to thepurge outlet of 6.1, and then connect the other end to the inletof the compone
12、nt or system to be sampled.NOTE 1If the system to be sampled is already connected to the filteredgas pressure supply, then establish the purge as noted in 6.1.6.3 Connect a suitable connecting line from the sample portto the inlet of the automatic monitor sensing device. (When nosample port is desig
13、nated, use the down-stream terminal pointfrom which purge gas is flowing.)6.4 Increase the purge to one of the following:1This practice is under the jurisdiction of ASTM Committee E21 on SpaceSimulation and Applications of Space Technology and is the direct responsibility ofSubcommittee E21.05 on Co
14、ntamination.Current edition approved Nov. 1, 2008. Published December 2008. Originallyapproved in 1972. Last previous edition approved in 2000 as F 327 78(2000).1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.4.1 8.49-dm3/min (0.3-
15、ft3/min) flow,6.4.2 34.5-kPa (5-psig) gage pressure, or6.4.3 5 % of system operating pressure when this pressure isless than 34.5-kPa (5-psig) gage.6.5 Surge Pressure Cleaning:6.5.1 Quickly increase the continuous purge pressure for a5-s duration, three times at 1-min intervals in accordance withone
16、 of the following:6.5.1.1 To 689.5-kPa (100-psig) gage pressure,6.5.1.2 To 113.2-dm3/min (4.0-ft3/min) flow,6.5.1.3 70 % of system operating pressure when this oper-ating pressure is below 689.5 kPa (100 psig) gage.6.5.1.4 In accord with a given system operation require-ment, but not to exceed the r
17、ated pressure of the sensing unit.6.5.2 Reduce the purge pressure to the level in 6.4 after eachsurge pressure application of 6.5.1 (that is during 1-mininterval).6.6 Connect a flowmeter to the outlet of the automaticmonitor sensor and adjust the flow versus time to achieve arequired sample volume w
18、ithin the capability of the sensor.Remove the flowmeter after adjusting the flow.6.7 Set automatic monitor display to zero.6.8 Simultaneously begin automatic particulate counting,sizing and timing of volumetric flow.6.9 Record particulate contamination counts on the monitordisplay for the required s
19、ample volume.6.10 Adjust the continuous purge to the level in 6.4.6.11 Evaluate results and if requirements of contaminationlevels are acceptable, disconnect the monitor and secure thesystem in accordance with the users requirements.6.12 If results are rejected, repeat 6.5-6.12.7. Precision7.1 Each
20、testing agency has the responsibility of judging theacceptability of its own results. The precision of the results isa function of the procedures (Note 2), facilities utilized, as wellas compliance to the recommended industry state-of-the-artpractices in cleanliness. Reproducible analysis determinat
21、ionsby different users can be achieved only with identical facilitiesand trained conscientious personnel.NOTE 2Every effort should be made to eliminate outside contamina-tion during operations.ASTM International takes no position respecting the validity of any patent rights asserted in connection wi
22、th any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible tech
23、nical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful considerat
24、ion at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Ha
25、rbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).FIG. 1 Filtered Gas SystemF327082
