1、Designation: E 1292 94 (Reapproved 2006)Standard Specification forGravity Convection and Forced Ventilation Incubators1This standard is issued under the fixed designation E 1292; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、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.1. Scope1.1 This specification covers the performance requirementsfor general purpose air incubators ordinarily used for
3、incubat-ing procedures, which have an incubating chamber up to 0.6m3(25 ft3) in volume. It is applicable to gravity and forcedventilation incubators designed to operate over all or part of thetemperature range from 5C above ambient to 75C.1.2 This specification does not include any requirements fort
4、he safe handling of harmful or disease bearing organisms.1.3 The following precautionary caveat pertains only to thetest method portions, Sections 4, 5, and 6, of this specification.This standard does not purport to address all of the safetyconcerns, if any, associated with its use. It is the respon
5、sibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.2. Types2.1 This specification covers the following four types of airincubators:2.1.1 Type 1AAn incubator ventilated by gravity convec-tion h
6、aving a uniformity of temperature within 3 % of thedifferential between incubator and ambient temperature,2.1.2 Type 1BAn incubator ventilated by gravity convec-tion having a uniformity of temperature within 6 % of thedifferential between incubator and ambient temperature,2.1.3 Type 2AAn incubator v
7、entilated by forced ventila-tion having a uniformity of temperature within 2 % of thedifferential between incubator and ambient temperature,2.1.4 Type 2BAn incubator ventilated by forced ventila-tion having a uniformity of temperature within 5 % of thedifferential between incubator and ambient tempe
8、rature.3. Performance Requirements3.1 The temperature within the incubating chamber shall becontrolled by an automatic device, and shall be uniform withinthe tolerances given in Table 1, when tested in accordance withSection 4.3.2 The rate of ventilation of the incubating chamber shallconform to the
9、 requirements specified in Table 1 for theparticular type of incubator when measured in accordance withthe procedure given in Section 5.3.3 The recovery time of the incubating chamber shallconform to the requirements specified in Table 1 for theparticular type of incubator, when tested in accordance
10、 with theprocedure specified in Section 6.4. Test Methods4.1 Temperature Uniformity:4.1.1 Place nine calibrated thermocouples (Note 1) madefrom iron-constantan or copper-constantan wires approxi-mately 0.5 mm in diameter (No. 24 gauge) and having ajunction size of not more than 2 mm (0.08 in.) in th
11、e emptyincubating chamber with shelves in place, and vents open.Locate one thermocouple in each of the eight corners of theincubator approximately 5 cm (2 in.) from each wall, and placethe ninth thermocouple within 2.5 cm (1 in.) of the geometriccenter of the chamber. A minimum length of 30 cm (12 i
12、n.) ofwire for each thermocouple shall be inside the incubator tominimize the conduction of heat from the thermocouple.NOTE 1If calibrated thermocouples are not available, nine thermo-couples made from the same spool of wire may be used, provided theygive the same value for temperature when placed a
13、djacent to one anotherin the incubating chamber at the temperature of the test.4.1.2 Bring the incubator to the specified temperature andallow it to reach a steady state (Note 2). Record the tempera-ture of the nine thermocouples for a period of at least 12 h anddetermine from the record the maximum
14、 deviation of eachpoint from the desired temperature. The ambient room tem-perature shall vary by not more than a total of 5C and the linevoltage shall not vary by more than a total of 5 % during thetest.NOTE 2Some incubators may require as much as 12 h to reach asteady state. If a steady state does
15、 not exist, there is a drift in thetemperature toward the steady state condition.5. Rate of Ventilation5.1 Seal the ventilation ports, doors, and all apertures of theincubator with adhesive tape, or by other means to prevent anyair from passing through the incubator (Note 3). Connect a Wh1This speci
16、fication is under the jurisdiction of ASTM Committee E41 onLaboratory Apparatus and is the direct responsibility of Subcommittee E41.06 onWeighing Devices.Current edition approved Nov. 1, 2006. Published December 2006. Originallyapproved in 1989. Last previous edition approved in 2001 as E 1292 94 (
17、2001).1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.meter with the smallest division reading in 0.01 Wh in theelectrical supply line to the incubator.NOTE 3In forced circulation incubators, the space around the motorshaft where it
18、enters the incubator must be closed, but the motor speedmust not be affected by the closure.5.2 Heat the incubator to its maximum rated temperature,and while at this temperature measure the electrical energyconsumption for a period of at least 4 h. Start and stop the testat corresponding points of t
19、he off-on cycle.5.3 Then remove the seals, open the ventilation ports, andmeasure the consumption of electrical energy in the samemanner as in 5.2. The ambient room temperature measured ata point approximately2m(6ft)from the incubator approxi-mately level with its base and at least 0.6 m (2 ft) from
20、 anysolid object must be the same within 0.2C during the two tests.5.4 Calculate the number of changes per h of the air in theincubating chamber from the following equation:N 5 3590X 2 Y!/VDDT (1)where:N = number of air changes per h,X = average power consumption during ventilation, ob-tained by div
21、iding the energy consumption deter-mined from the Wh meter reading by the duration ofthe test in hours,Y = average power consumption with no ventilation,computed in the same manner as X.V = volume of the incubating chamber in cm3,D = density of the ambient room air during the test ing/cm3, andDT = d
22、ifference in temperature between the incubatingchamber and the ambient room air in degrees Cel-sius.6. Recovery Time6.1 Place one thermocouple made from iron-constantan orcopper-constantan wires approximately 0.5 mm in diameter(No. 24 gauge) and having a junction size of not more than 2mm (0.08 in.)
23、 in the empty chamber with shelves in place, andvents open. Locate the thermocouple within 2.5 cm (1 in.) ofthe geometric center of the chamber.6.2 Bring the incubator to 37C and allow it to reach asteady state (Note 2). Record the temperature for12 h. Openthe outer and inner doors for 30 6 1 s. Clo
24、se the doors andmeasure the time required for the chamber to come back withinthe uniformity band for the type of incubator being tested, at37C.7. Keywords7.1 convection; forced; gravity; incubators; ventilationASTM International takes no position respecting the validity of any patent rights asserted
25、 in connection with 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
26、 responsible technical 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 c
27、areful consideration 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 Internati
28、onal, 100 Barr Harbor 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 th
29、e ASTM website(www.astm.org).TABLE 1 Performance Requirements for IncubatorsCharacteristic Type 1A Type 1B Type 2A Type 2BDeviation from specified temperature of test throughout incubating chamberduring the 12 h period. Maximum percent of the differential between ambientand test temperature. Numbers in parentheses are for chamber temperature of37C and ambient of 25C3 (0.4C) 6 (0.7C) 2 (0.25C) 5 (0.6C)Rate of Ventilation in Air Changes per Hmin 1122max 3355Recovery Time in Min, max 12 16 5 9E 1292 94 (2006)2
