1、Designation: E715 80 (Reapproved 2011)Standard Specification forGravity-Convection and Forced-Circulation Water Baths1This standard is issued under the fixed designation E715; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r 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 specification covers the performance requirementsfor general-purpose water baths ordinarily used in testingo
3、perations. It is applicable to gravity-convection and forced-circulation water baths operating in the range from 5C aboveambient to 100C and having a water volume up to 100 L.1.2 This specification covers unloaded, covered water baths.2. Classification2.1 This specification covers the following four
4、 types ofwater baths:2.1.1 Type IAA gravity-convection bath having a unifor-mity of temperature not greater than 62 % of the differentialbetween ambient and operating temperature.2.1.2 Type IBA gravity-convection bath having a unifor-mity of temperature not greater than 64 % of the differentialbetwe
5、en ambient and operating temperature.2.1.3 Type IIAA forced-circulation bath having a unifor-mity of temperature not greater than 61 % of the differentialbetween ambient and operating temperature.2.1.4 Type IIBA forced-circulation bath having a unifor-mity of temperature not greater than 62 % of the
6、 differentialbetween ambient and operating temperature.NOTE 1Uncovered water baths will generally have uniformitiesbroader by an additional 0.1C.3. Performance Requirements3.1 The temperature within the bath chamber shall becontrollable by an automatic device and shall be uniformwithin the tolerance
7、s given in Table 1 for the particular type ofbath when tested in accordance with 4.1.3.2 The “time constant” is an arbitrary measure of the rate atwhich a standard specimen is heated following the procedureof 4.2. The value of the time constant shall not exceed themaximum value given in Table 1 for
8、the particular type of bath.4. Test Methods4.1 Temperature Uniformity:4.1.1 Place five calibrated temperature sensors in the un-loaded water bath with diffuser plate in place and at lowestposition and water level approximately 38 mm (1.5 in.) fromthe top. Temperature sensors may be platinum resistan
9、ceelements or thermistors having a time constant of 2.5 s or less,or thermocouples made of iron or copper-constantan wireapproximately 0.5 mm (24-gauge) in diameter and having ajunction size not larger than 2 mm (0.08 in.). Locate one sensorin each of the four corners of the bath approximately 50 mm
10、 (2in.) from each wall and midway between the diffuser plate andthe water surface. Locate the fifth sensor within 25 mm (1 in.)of the geometric center of the bath. Cover the bath either withthe standard cover used with the bath or a flat sheet of stainlesssteel. If necessary, holes may be made in th
11、e cover, in theproper locations to accommodate the sensors. Rubber stoppersshall be used to plug the holes in order to minimize vapor loss.NOTE 2If calibrated thermocouples are not available, five thermo-couples made from the same spool of wire may be used, provided theygive the same value for tempe
12、rature when placed adjacent to one anotherin the bath at test temperature.4.1.2 Bring the bath to the desired temperature and allow itto reach a steady state. Record the temperatures of the fivesensors for a period of 3 h. Determine from the record themaximum deviation in both plus and minus directi
13、on from thedesired temperature. Ambient temperature shall not vary bymore than a total of 4C and the line voltage shall not vary bymore than a total of 5 % during the test.4.2 Time Constant:4.2.1 Heat the bath to 60C and allow it to stabilize for 1 h.Prepare a differential thermocouple using 24-gaug
14、e iron-constantan thermocouple wire. There should be approximately1 m (39 in.) between junctions.4.2.2 Fill two 500-mL Erlenmeyer flasks with water. Placeone junction of the differential thermocouple in each flask. Thejunction should be about 35 mm (138 in.) from the bottom andcentered. Stopper each
15、 flask.1This specification is under the jurisdiction of ASTM Committee E41 onLaboratory Apparatus and is the direct responsibility of Subcommittee E41.01 onApparatus.Current edition approved Dec. 1, 2011. Published December 2011. Originallyapproved in 1980. Last previous edition approved in 2006 as
16、E715 80 (2006).DOI: 10.1520/E0715-80R11.TABLE 1 Performance Requirements for BathsCharacteristicTypeIATypeIBTypeIIATypeIIBUniformity (differential betweenambient and testtemperature), 6 %2412Maximum time constant, min 26 26 20 201Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West
17、 Conshohocken, PA 19428-2959, United States.4.2.3 Connect the differential thermocouple to a strip chartrecorder. Start recorder and establish a steady base line.Immerse one flask in the approximate center of the bath.Record the time required to reach the new steady state. This isthe time constant.5
18、 Keywords5.1 forced circulation; gravity-convection water bathsASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any suc
19、h 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 technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invite
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21、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 Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this
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