ASTM D4913-2000(2011) Standard Practice for Determining Concentration of Hydrogen Sulfide by Direct Reading Length of Stain Visual Chemical Detectors《用直读法 污染程度 可见化学检测器测定硫化氢的浓度的标准操作.pdf

《ASTM D4913-2000(2011) Standard Practice for Determining Concentration of Hydrogen Sulfide by Direct Reading Length of Stain Visual Chemical Detectors《用直读法 污染程度 可见化学检测器测定硫化氢的浓度的标准操作.pdf》由会员分享，可在线阅读，更多相关《ASTM D4913-2000(2011) Standard Practice for Determining Concentration of Hydrogen Sulfide by Direct Reading Length of Stain Visual Chemical Detectors《用直读法 污染程度 可见化学检测器测定硫化氢的浓度的标准操作.pdf（4页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: D4913 00 (Reapproved 2011)Standard Practice forDetermining Concentration of Hydrogen Sulfide by DirectReading, Length of Stain, Visual Chemical Detectors1This standard is issued under the fixed designation D4913; the number immediately following the designation indicates the year oforig

2、inal adoption 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 covers the detection of hydrogen sulfidegas by vi

3、sual chemical detectors. Included under visual chemi-cal detectors are: short-term detector tubes (1),2long-termdetector tubes (2), and length-of-stain dosimeters (3). Diffusiontubes are not included under this practice because they are notdirect reading, and spot tests are not included because of t

4、heirpoor accuracy. The sample results are immediately available byvisual observation, thus no analytical equipment is needed.1.2 This practice reflects the current state-of-the-art forcommercially available visual length-of-stain detectors forhydrogen sulfide. Any mention of a specific manufacturer

5、inthe text or references does not constitute an endorsement byASTM.1.3 The values stated in SI units are to be regarded asstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establi

6、sh appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3D1356 Terminology Relating to Sampling and Analysis ofAtmospheresD3686 Practice for Sampling Atmospheres to Collect Or-ganic Compound Vapors

7、(Activated Charcoal Tube Ad-sorption Method)D4490 Practice for Measuring the Concentration of ToxicGases or Vapors Using Detector TubesD4599 Practice for Measuring the Concentration of ToxicGases or Vapors Using Length-of-Stain Dosimeters2.2 Other Documents:CFR 1910.1000 Federal Occupational Safety

8、and HealthStandard Title 29, Part 1910.1000, Subpart Z, and Part1926.55, Subpart D4NIOSH Criteria for a Recommended Standard, Occupa-tional Exposure to Hydrogen Sulfide, 19775Threshold Limit Values for Chemical Substances in theWork Environment Adopted by the American Conferenceof Governmental Indus

9、trial Hygienists, latest issue62.3 ANSI Standard:ANSI/ISEA 1021990(R1998) Gas Detector Tube Units-Short-Term Type for Toxic Gases and Vapors in WorkingEnvironments73. Terminology3.1 DefinitionsFor definitions of terms used in thismethod, refer to Terminology D1356.4. Summary of Practice4.1 In genera

10、l, the length-of-stain visual detectors describedin this practice consist of a sealed glass tube filled with areactive chemical dispersed on a granular material or a paperstrip. This reactive material is sensitive to hydrogen sulfide andchanges color upon exposure to hydrogen sulfide gas. Thesedetec

11、tors are designed so that the length of the color change inthe tube is related to the concentration of hydrogen sulfideunder conditions of sampling volume or sampling time speci-fied by the manufacturer. These detectors are typically cali-brated by the manufacturer on an individual lot basis. Threeg

12、eneral types of detectors are in current use.1This practice is under the jurisdiction of ASTM Committee D22 on Air Qualityand is the direct responsibility of Subcommittee D22.04 on Workplace Air Quality.Current edition approved March 1, 2011. Published March 2011. Originallyapproved in 1989. Last pr

13、evious edition approved in 2005 as D4913 - 051. DOI:10.1520/D4913-00R11.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard practice.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. F

14、or Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Code of Federal Regulations, available from the U.S. Government PrintingOffice Superintendent of Documents, 732 N. Capitol St., NW, Mail Stop: SDE,Washington, DC 20401.5Available from

15、 National Technical Information Service (NTIS), 5285 PortRoyal Rd., Springfield, VA 22161, http:/www.ntis.gov.6Available from American Conference of Governmental Industrial Hygienists,Inc. (ACGIH), 1330 Kemper Meadow Dr., Cincinnati, OH 45240, http:/www.acgih.org.7Available from American National St

16、andards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.1.1 Short-Term Detector TubesA given volume of air(specified by the manufacturer) is pulled

17、through the tube by apump in a time period on the order of 1 to 10 min. Thelength-of-stain is related to the amount of air sampled and thehydrogen sulfide concentration during the sample period.4.1.2 Long-Term Detector TubesThe air sample is pulledthrough the tube at a slower, constant flow rate (sp

18、ecified bythe manufacturer) by an electrical pump over a 1- to 8-h timeperiod. The length of color change and the sampling time areused to estimate the time weighted average (TWA) concentra-tion of hydrogen sulfide.4.1.3 Length-of-Stain Dosimeter TubesThis detector typesamples the atmosphere to be t

19、ested by diffusion; no pump isrequired. Sampling times are on the order of 1 to 8 h and thestain length as a function of sampling time is related to theTWA concentration of hydrogen sulfide.4.2 Information on the correct use of detector tubes andlength-of-stain dosimeters is presented.5. Significanc

20、e and Use5.1 GeneralHydrogen sulfide is nearly ubiquitous. Itoccurs naturally in volcanic gases, in sulfur springs andfumaroles, in decaying of plant and animal protein, and inintestines as a result of bacterial action. Hydrogen sulfide is aserious hazard to the health of workers employed in energyp

21、roduction from hydrocarbon or geothermal sources, in theproduction of fibers and sheets from viscose syrup, in theproduction of deuterium oxide (heavy water), in tanneries,sewers, sewage treatment and animal waste disposal, in workbelow ground, on fishing boats, and in chemical operations,including

22、the gas and oil industry.5.2 In 29 CFR 1910.1000, the Federal Occupational Safetyand Health Administration designates that worker exposure tocertain gases and vapors must not be exceeded in workplaceatmospheres at concentrations above specific values, averagedover a certain time span. Hydrogen sulfi

23、de is included in thislist. Refer also to NIOSH Criteria for a Recommended Stan-dard, Occupational Exposure to Hydrogen Sulfide.5.3 This practice will provide means for the determinationof airborne concentrations of hydrogen sulfide.5.4 This practice provides means for either personal or areasamplin

24、g and for short-term or time-weighted average (TWA)measurements. Refer to Threshold Limit Values for ChemicalSubstances in the Work Environment.6. Detector Tubes, Short-Term (1,4-9)6.1 GeneralShort-term detector tubes are used for grab-sampling. They allow determination of hydrogen sulfide con-centr

25、ations in approximately five min.6.2 Apparatus:6.2.1 Detector tubes for the detection of hydrogen sulfideand an appropriate pump are required. Because manufacturershave different tubes for different measurement ranges ofhydrogen sulfide, an estimate of the expected hydrogen sulfideconcentration is h

26、elpful. Detector tubes made by one manufac-turer must not be used with pumps made by a differentmanufacturer (10).6.2.2 The Safety Equipment Institute (SEI) has a voluntarycertification program for short-term detector tubes for hydro-gen sulfide. This program consists of independent laboratoryverifi

27、cation of sampling pump precision and of detector tubeperformance. The pump and tube units certified under thisprogram are listed in the SEI Approved Equipment List. Thecertification test protocol is similar to that used in the nowdiscontinued NIOSH Certification Program (11,12,13).6.2.3 In some sam

28、pling situations, particularly when testingfor hazardous hydrogen sulfide concentrations in confinedspaces, a remote sampling line and adapter can be used. Thisallows placement of the detector tube in the potentiallyhazardous area to be tested while the operator is in a safer area.6.3 Procedure:6.3.

29、1 Carefully follow the instruction sheet of the manufac-turer for the proper use of hydrogen sulfide short-term detectortubes (see Practice D4490).6.3.1.1 Check the pump for leaks, total volume, and flowrate in accordance with the instruction manual for the pump.Also check the sampling line for leak

30、s (if used).6.3.1.2 Remove one detector tube from the box and breakoff both tips.6.3.1.3 Insert the detector tube into the tube holder of thepump or onto the sample line, making sure that it is properlyoriented.6.3.1.4 Face the mounted detector tube into the atmosphereto be tested. Sample an appropr

31、iate volume of air by pulling thepump handle out the required number of strokes, if using apiston pump, or squeezing the pump the proper number oftimes, if using a bellows-type or bulb-type pump.6.3.1.5 If hydrogen sulfide is present, the indicator chemicalin the tube will change color from white to

32、 brown or gray. Thelength of stain, correlated with the volume of air sampled, willindicate the concentration. Most detector tubes now have directreading concentration scales printed on the tube.6.3.1.6 For the most reliable estimate of the hydrogensulfide concentration, the maximum number of pump s

33、trokes(as specified by the manufacturer) should be taken so that thestained length is between 20 and 80 % of the total indicatingchemical length. At very low or very high concentrations, thisis not always possible.6.4 InterferencesWhen using lead salts as the impregnant,sulfur dioxide, nitrogen diox

34、ide, and mercaptans can interferewith accurate measurements, particularly at low hydrogensulfide concentrations. Sulfur dioxide, if present at comparableconcentrations to hydrogen sulfide, will give a positive inter-ference, that is, will increase the length of stain; however,sulfur dioxide by itsel

35、f will cause no stain. Mercaptans at ornear their TLV levels will not interfere, but at high concentra-tions (more than 100 ppm) they can give a positive interfer-ence. Nitrogen dioxide, at concentrations near its TLV, gives aslight negative error. The effect of these interferences isminimal when si

36、lver cyanide, copper, or mercury compoundsare used as the impregnant.6.5 The accuracy of detector tubes from two manufacturerswas tested over a temperature range of 4C 40F to 49C120F and over a relative humidity range of 20 % to 90 %(14). The accuracy of these hydrogen sulfide detector tubes wasredu

37、ced only at high temperatures (one manufacturer).D4913 00 (2011)26.6 Measurement RangeHydrogen sulfide tubes are avail-able to measure concentrations from 0.5 to 70,000 ppm.6.7 AccuracySEI certified detector tubes must have anaccuracy (precision plus bias) of 625 % of the actual concen-tration or be

38、tter for hydrogen sulfide concentrations from 10 to50 ppm. At 5 ppm the accuracy must be better than 635 %. Atconcentrations higher than 50 ppm, a minimum accuracy is notspecified in the SEI requirements, but is typically better than625 %. Manufacturers of non-SEI certified hydrogen sulfidedetector

39、tubes typically claim accuracies of better than 25 to35 %.6.8 ReagentsThe reagent system used to detect the pres-ence of hydrogen sulfide is either lead acetate, a mercurycomplex, a copper salt, or silver cyanide. These salts areimpregnated on either granular alumina or silica gel.7. Detector Tubes,

40、 Long-Term (2,15,16)7.1 GeneralLong-term sampling equipment detects andmeasures hydrogen sulfide over an entire work shift (orfraction thereof) without the need for time consuming labora-tory analysis. This system measures a time-weighted-average(TWA) concentration.7.2 ApparatusDetector tubes for de

41、tecting hydrogen sul-fide and an electrical pump for pulling the sample through thetube at a low rate, such as 5 to 20 mL/min.7.3 Procedure:7.3.1 Carefully follow the instruction sheet of the manufac-turer for the proper use of hydrogen sulfide long-term tubes.7.3.1.1 Check the pump for proper flow

42、rate or volume perpump stroke in accordance with the instruction manual for thepump.7.3.1.2 Remove one detector tube from the box and breakoff both tips.7.3.1.3 Insert the tube into the tube holder, making sure it isproperly oriented.7.3.1.4 If necessary, connect the tube holder to the pump.With som

43、e systems, the tube is connected directly to the pumpwithout the use of a tube holder.7.3.1.5 Set the pump to the proper flow rate and turn it on.Record the starting time. For accurate work, the flow rate of thepump should be calibrated under actual use conditions. Referto appropriate Annex of Pract

44、ice D3686.7.3.1.6 Continue sampling for the length of time desired,within the ppm-h capability of the tube. Record the time at theend of sampling.7.3.1.7 If hydrogen sulfide is present, a brownish staindevelops in the detector chemical. To determine the concen-tration, either read the ppm-h directly

45、 from the tube and divideby the sampling time (h) or refer to a calibration graph, findingthe point of intersection of the stain length and the samplingtime and read from the graph the corresponding concentration.7.4 InterferencesThe interferences are the same as forshort-term hydrogen sulfide tubes

46、 (see 6.4).7.5 Temperature and relative humidity have little effect as inthe case of short-term detector tubes.7.6 Measurement range 0.5 to 100 ppm.7.7 AccuracyTypical accuracy (precision plus bias) forlong-term detector tubes is better than 625 % of the actualconcentration (16).7.8 Reagents same as

47、 short-term tubes (see 6.8).8. Length-of-Stain Dosimeters (3,17,18)8.1 GeneralHydrogen sulfide length-of-stain dosimetersmeasure TWA concentrations. They operate by diffusion and,therefore, require no auxiliary equipment. They detect andmeasure hydrogen sulfide over periods from 0.5 to 8.0 h (orlong

48、er) without the need for laboratory analysis.8.2 ApparatusAll that is required is a hydrogen sulfidelength-of-stain dosimeter and the dosimeter holder supplied bythe manufacturer. Dosimeters and holders supplied by differentmanufacturers should not be interchanged.8.3 Procedure:8.3.1 Carefully follo

49、w the instruction sheet of the manufac-turer for the proper use of hydrogen sulfide length-of-staindosimeter tubes (see Practice D4599).8.3.1.1 The dosimeter is opened at one end to allow diffu-sion of the gas into the tube.8.3.1.2 The tube is mounted into a tube holder, which can beclipped onto a collar or pocket for personal monitoring, or ontoa stationary object for area monitoring.8.3.1.3 The chemically impregnated paper or gel within thetube changes color from white to brownish if hydrogen sulfideis present.8.3.1.4 The length of color stain and the ti