1、Designation: D 4913 00 (Reapproved 2005)e1Standard Practice forDetermining Concentration of Hydrogen Sulfide by DirectReading, Length of Stain, Visual Chemical Detectors1This standard is issued under the fixed designation D 4913; the number immediately following the designation indicates the year of
2、original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEThis practice was corrected editorially in October 2005.1. Scope
3、1.1 This practice covers the detection of hydrogen sulfidegas by visual 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
4、are notdirect reading, and spot tests are not included because of theirpoor 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 det
5、ectors forhydrogen sulfide. Any mention of a specific manufacturer 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 u
6、se. 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.2. Referenced Documents2.1 ASTM Standards:3D 1356 Terminology Relating to Sampling and Analysis ofAtmospheresD 3686 P
7、ractice for Sampling Atmospheres to Collect Or-ganic Compound Vapors (Activated Charcoal Tube Adsorp-tion Method)D 4490 Practice for Measuring the Concentration of ToxicGases or Vapors Using Detector TubesD 4599 Practice for Measuring the Concentration of ToxicGases or Vapors Using Length-of-Stain D
8、osimeters2.2 Other Documents:CFR 1910.1000 Federal Occupational Safety 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 theW
9、ork Environment Adopted by the American Conferenceof Governmental Industrial 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 thi
10、smethod, refer to Terminology D 1356.4. Summary of Practice4.1 In general, 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 su
11、lfide andchanges color upon exposure to hydrogen sulfide gas. Thesedetectors 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 typi
12、cally cali-brated by the manufacturer on an individual lot basis. Threegeneral 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 WorkplaceAtmospheres.Current edition approved O
13、ct. 1, 2005. Published January 2006. Originallyapproved in 1989. Last previous edition approved in 2000 as D 4913 - 00.2The 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, orcont
14、act ASTM Customer Service at serviceastm.org. For 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
15、 Stop: SDE,Washington, DC 20401.5Available from National Technical Information Service (NTIS), U.S. Depart-ment of Commerce, 5285 Port Royal Rd., Springfield, VA 22161.6Available from American Conference of Governmental Industrial Hygienists,Inc. (ACGIH), 1330 Kemper Meadow Dr., Suite 600, Cincinnat
16、i, OH 45240.7Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.1Copyright 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
17、the manufacturer) is pulled 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 sl
18、ower, constant flow rate (specified 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 typesa
19、mples the atmosphere to be tested 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
20、 is presented.5. Significance 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
21、 workers employed in energyproduction 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 ch
22、emical operations,including 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 certa
23、in time span. Hydrogen sulfide 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 ei
24、ther personal or areasampling 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 o
25、f hydrogen sulfide con-centrations 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 hydrog
26、en sulfideconcentration is helpful. 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
27、independent laboratoryverification 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
28、(11,12,13).6.2.3 In some sampling 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 s
29、afer area.6.3 Procedure:6.3.1 Carefully follow the instruction sheet of the manufac-turer for the proper use of hydrogen sulfide short-term detectortubes (see Practice D 4490).6.3.1.1 Check the pump for leaks, total volume, and flowrate in accordance with the instruction manual for the pump.Also che
30、ck the sampling line for leaks (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
31、 be tested. Sample an appropriate 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 wi
32、ll change color from white to 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,
33、 the maximum number of pump strokes(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,
34、sulfur dioxide, nitrogen dioxide, 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; ho
35、wever,sulfur dioxide by itself 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 in
36、terferences isminimal when silver 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 s
37、ulfide detector tubes wasreduced only at high temperatures (one manufacturer).D 4913 00 (2005)e126.6 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
38、 the actual concen-tration or better 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 cer
39、tified hydrogen sulfidedetector 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
40、or silica gel.7. Detector Tubes, 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.
41、2 ApparatusDetector tubes for detecting 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
42、 Check the pump for proper flow 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
43、tube holder to the pump.With some 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. Re
44、ferto appropriate Annex of Practice D 3686.7.3.1.6 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-tratio
45、n, either read the ppm-h directly 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 for
46、short-term hydrogen sulfide tubes (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 actualconcen
47、tration (16).7.8 Reagents same as 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
48、periods from 0.5 to 8.0 h (orlonger) 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.
49、3 Procedure:8.3.1 Carefully follow the instruction sheet of the manufac-turer for the proper use of hydrogen sulfide length-of-staindosimeter tubes (see Practice D 4599).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 le
