1、Designation: E 2251 07Standard Specification forLiquid-in-Glass ASTM Thermometers with Low-HazardPrecision Liquids1This standard is issued under the fixed designation E 2251; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、 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.1. Scope1.1 The purpose of this standard is to specify liquid-in-glassASTM thermometers using low hazard thermometric liquids
3、defined in this standard.1.2 This standard specifies liquid-in-glass thermometersgraduated in degrees Celsius or degrees Fahrenheit that arefrequently identified and used in methods under the jurisdictionof the various technical committees within ASTM. The currentapproved thermometers are listed in
4、Table 1.1.3 The technical requirements for the thermometric liquidsused in the thermometers in Table 1 are specified in Annex A1.Tests for conformity to the technical requirements are alsofound in Annex A1.NOTE 1It has been found by experience that ASTM Thermometers,although developed in general for
5、 specific tests, may also be foundsuitable for other applications, thus precluding the need for new thermom-eter specifications differing in only minor features. However, it issuggested that technical committees contact E20.05 before choosing acurrently designated thermometer for a new method to be
6、sure thethermometer will be suitable for the intended application.1.4 For full rationale, see Appendix X1.1.5 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 establish appro-priate safety an
7、d health practices and determine the applica-bility of regulatory requirements prior to use.2. Referenced Documents2.1 ASTM Standards:2E1 Specification for ASTM Liquid-in-Glass ThermometersE77 Test Method for Inspection and Verification of Ther-mometersE 344 Terminology Relating to Thermometry and H
8、ydrom-etryE 563 Practice for Preparation and Use of an Ice-Point Bathas a Reference Temperature3. Terminology3.1 DefinitionsThe definitions given in TerminologyE 344 apply.3.2 Definitions of Terms Specific to This Standard:3.2.1 bulb length, nthe distance from the bottom of thebulb to the junction o
9、f the bulb and the stem tubing.3.2.2 contraction chamber, nan enlargement of the cap-illary, located below the main scale or between the main scaleand the auxiliary scale, that serves to reduce the scale length orto prevent contraction of all the liquid column into the bulb.3.2.3 diameter, nthe larg
10、est outside dimension of theglass tubing as measured with a ring gage.3.2.4 expansion chamber, nan enlargement at the top ofthe capillary to provide protection against breakage caused byexcessive gas pressure.3.2.5 faden thermometer, na thermometer with a long,thin bulb used to determine emergent st
11、em temperatures.3.2.6 interval error, nthe deviation of the nominal valueof a temperature interval from its true value; either for the totalrange (total interval) or for a part of the range (partial interval).3.2.7 low-hazard liquid, na liquid that is biodegradable,non-hazardous and considered non-t
12、oxic in thermometer quan-tities.NOTE 2It is the responsibility of the manufacturer to determine thesuitability of a liquid for this standard. In marking the thermometer withtheASTM designation the manufacturer is confirming that the liquid in thethermometer is non-hazardous as defined by current OSH
13、A (OccupationalSafety and Health Administration) standards and non-toxic in thermom-eter quantities per current definitions of the United States EnvironmentalProtection Agency.3.2.8 thermometric liquid, nthe liquid in a liquid-in-glassthermometer that indicates the value of temperature.3.2.9 top of
14、the thermometer, nthe top of the finishedinstrument.3.2.10 total length, nthe distance from the bottom of thebulb to the top of the finished thermometer, including anyspecial finish at the top.1This specification is under the jurisdiction of ASTM Committee E20 onTemperature Measurement and is the di
15、rect responsibility of Subcommittee E20.05on Liquid-in-Glass Thermometers and Hydrometers.Current edition approved Nov. 1, 2007. Published Janaury 2008. Originallyapproved in 2003. Last previous edition approved in 2003 as E 225103s.2For referenced ASTM standards, visit the ASTM website, www.astm.or
16、g, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.3 Other ter
17、ms may be found in the Terminology sectionsof Specification E1and Test Method E77.4. Specifications4.1 The individual thermometers shall conform to the de-tailed specifications given in Table 1, the general requirementsspecified in Sections 5-15, and Annex A1 and Annex A2.NOTE 3Thermometers manufact
18、ured to previous revisions of thisstandard shall retain the same ASTM status as those meeting currentspecifications.NOTE 4The encapsulation (jacketing) of the glass of liquid-in-glassthermometers with polyflourinated hydrocarbons will change their perfor-mance and physical characteristics, including
19、, but not limited to, responsetime, accuracy, and physical dimensions. Therefore, under no circum-stances should an encapsulated or otherwise modifiedASTM thermometerbe used in performing tests that specify the use of an ASTM thermometer.5. Type5.1 Each thermometer in Table 1 shall be of the liquid-
20、in-glass type filled with a low hazard thermometric liquid thatmeets the specifications in Annex A1. The gas filling above theliquid shall be nitrogen or other suitable inert gas. The fillinggas shall be chosen to have very low solubility in thethermometric fluid.6. Stem6.1 StemThe stem shall be mad
21、e of suitable thermometertubing and shall have a plain front and enamel back.6.2 Top FinishThe top of all thermometers specified inTable 1 shall have a plain rounded finish, except the following,which shall have the top finish indicated below:6.2.1 Special Finish:6.2.1.1 Any finish suitable for asse
22、mbly in a standard304.8-mm (12-in.) non-sparking metal armor with open face;in a cup case assembly; or in a flushing case assembly asdefined in standards the thermometers are used in:Thermometers S59C, S59F7. Bulb7.1 The bulb shall be made of glass having a viscosity of atleast 1014.6poises at 490C
23、(914F) and at least 1013.4poises at520C (968F).NOTE 5Thermometers made with bulb glasses having propertiesclose to these minimum requirements should not be subjected to tempera-tures above 405C (760F) or be continuously exposed to temperaturesabove 370C (700F).8. Capillary Clearances8.1 The followin
24、g distances between graduations and thebulb, and between graduations and enlargements in the capil-lary, are minimum limits acceptable for thermometers in thisstandard.NOTE 6In order for a thermometer to be usable over its entiregraduated range, graduation marks must not be placed too close to anyen
25、largement in the capillary. Insufficient immersion of the thermometricliquid in the main bulb or capillary enlargement, graduation marks placedover parts of the capillary that have been changed by manufacturingoperations, or graduations so close to the top of the thermometer thatexcessive gas pressu
26、re results when the thermometric liquid is raised tothis level, may lead to appreciable errors.8.1.1 A 13-mm length of unchanged capillary between thebulb and the immersion line or lowest graduation, if thegraduation is not above 100C (212F); a 30-mm length if thegraduation is above 100C (212F).8.1.
27、2 A 5-mm length of unchanged capillary between anenlargement and the graduation next below, except at the top ofthe thermometer.8.1.3 A 10-mm length of unchanged capillary between anenlargement, other than the bulb, and the immersion line or thegraduation next above, if the graduation is not above 1
28、00C(212F); a 30-mm length if the graduation is above 100C(212F).8.1.4 A 10-mm length of unchanged capillary above thehighest graduation, if there is an expansion chamber at the topof the thermometer; a 30-mm length if there is no expansionchamber. For the purposes of this requirement, “an expansionc
29、hamber” is interpreted as an enlargement at the top end of thecapillary bore that shall have a capacity equivalent to not lessthan 20 mm of unchanged capillary.8.2 Due to a change in the methods used for scale place-ment, it is possible to manufacture thermometers that complywith the specifications
30、given in Table 1, but not meet therequirements for capillary clearances given above. In any case,the distances given in this section are the governing factor.Under no circumstances shall the scales on thermometers beplaced closer than these minimum distances.9. Graduations and Inscriptions9.1 All gr
31、aduation lines, figures, and letters shall be clearlydefined, suitably colored, and permanent. The width and thesharpness of the graduation lines shall be designed in accor-dance with necessary space between the graduations and thedesired accuracy of interpolation. The middle of the graduationline s
32、hall be accurately determinable.9.1.1 A suitably etched thermometer with the etched linesand figures filled with a suitable colorant shall be consideredpermanently marked provided it passes the test for permanencyof pigment in Test Method E77.9.2 Graduation LinesAll graduation lines shall bestraight
33、, of uniform width, and perpendicular to the axis of thethermometer. The width of the graduation lines shall be asfollows:9.2.1 Group 1Maximum line width 0.10 mm; for ther-mometers that may read to fractions of a division, often withmagnifying aids:Thermometers S56C, S56F, S62C, S62F, S63C, S63F, S6
34、4C, S64F,S65C, S65F, S66C, S66F, S67C, S67F, S91C, S116C, S117C,S120C9.2.2 Group 2Maximum line width 0.15 mm; for ther-mometers that may be read to the nearest half division or wherethe congestion of scale dictates the use of a scale to moderatefineness:Thermometers S12C, S12F9.2.3 Group 3Maximum li
35、ne width 0.20 mm; for ther-mometers with more open scales, usually read to the nearestdivision, often times under adverse conditions where a boldgraduation is therefore desired:Thermometers S59C, S59FE22510729.3 Immersion LineOn partial immersion thermometersan immersion line shall be permanently ma
36、rked on the front ofthe thermometer at the distance above the bottom of the bulb asspecified in Table 1 within a tolerance of 60.5 mm. Theimmersion inscription shall be written in capital letters andabbreviated (for example, 76 mm immersion shall be written76 MM IMM.)9.4 Terminal NumbersThe terminal
37、 number shall be infull when there are one or more numbered graduations betweenit and the next full number. This rule need not necessarily befollowed for:9.4.1 Precision Thermometers:S65F, S66F, S67C, and S67F9.5 Scale Below ZeroWhen a scale extends both aboveand below 0C or 0F, the two parts of the
38、 scale shall bedifferentiated by some means. Examples of suitable means are:9.5.1 Different colorants for the graduations for the twoparts of the scale,9.5.2 Different style of numerical characters for the twoparts of the scale, and9.5.3 Use of minus signs before appropriate numbers below0C or 0F.10
39、. Special Inscription10.1 The special inscription specified in Table 1 shall bemarked on the thermometer in capital letters and Arabicnumbers without the use of periods. Include year of currentrevision in the ASTM designation (for example ASTM S56C-03).10.1.1 Each thermometer shall be permanently ma
40、rked witha unique serial number and the manufacturers tradename ormark.10.1.2 Each thermometer shall have the average coefficientof thermal expansion of the liquid permanently marked.10.1.3 When the length of the thermometer permits, thewords “TOTAL IMMERSION” may also be inscribed on theback of the
41、rmometers calibrated for total immersion.11. Permanency of Pigment11.1 The test for permanency of pigment shall be performedon any convenient portion of the scale section of the thermom-eter. The pigment shall not chalk, burn out, or loosen as a resultof this test (see Test Method E77).12. Bulb Stab
42、ility12.1 No test for bulb stability is necessary for any thermom-eters currently in this standard. However, should there be in thefuture, the bulb stability test as found in Specification E1shallbe used.13. Scale Error13.1 Thermometers shall be verified and calibrated at thetemperatures specified i
43、n Table 4. Partial immersion thermom-eters shall be calibrated for the emergent stem temperaturesspecified in Table 4 using faden thermometers.13.1.1 At the time of purchase, the scale errors must bewithin the maximum scale error found in Table 1. Theindications of many high temperature and fraction
44、ally gradu-ated thermometers may change with time and continued use,due to minute changes in bulb volume. Periodic verification ofthese thermometers either over the entire scale or reverificationat the reference temperature (ice point or steam point), inaccordance with procedures set forth in Test M
45、ethod E77,isrecommended.13.2 Due to the application requirements for range andconstruction of the following thermometer(s) do not havereference points such as ice and steam points:S91C14. Case and Instructions14.1 Each thermometer shall be supplied in a suitable caseon which shall appear the followi
46、ng marking (except when atransparent case is used): the letters “ASTM,” the thermometernumber (S59C, S59F, etc.), and the temperature range.14.2 Each thermometer shall be supplied with suitable userinstructions. See Appendix X2 for Sample User Instructions.15. Methods of Verification and Calibration
47、15.1 Thermometers shall be verified and calibrated at thespecified immersion in accordance with Test Method E77. Forpartial immersion thermometers careful consideration to emer-gent stem temperatures shall be observed.E2251073TABLE1SpecificationforE2251ASTMThermometersAlldimensionsareinmillimetres.S
48、eeTable4forVerificationandCalibrationTemperatures.FIGA.GeneralReferenceFigureforTable1(SpecificfiguresassociatedwithindividualthermometersarefoundattheendofTable4)ExplanatoryNotesforTable1(numberscorrespondtothosefoundinTable1ofSpecificationE1wheneverpossible):AAnexpansionchamberisprovidedforreliefo
49、fgaspressuretoavoiddistortionofthebulbathighertemperatures.Itisnotforthepurposeofjoiningthermometricliquidseparationsandundernocircumstancesshouldthethermometerbeheatedabovethehighesttemperaturereading.MForkinematicviscositythermometers,theice-pointreadingshallbetakenwithin1hafterbeingatthetesttemperaturefornotlessthan3min.Theice-pointreadingshallbeexpressedtothenearest0.01Cor0.02FandappliedasexplainedinTestMethodE77,Section13.OCapillaryclearancesmustconformtoSection8.YOveranyintervalof2Cthechangeinclaibrationcorrectionshallnotexceed0.
