1、_SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
2、rom, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.Copyright 2012 SAE InternationalAll rights reserved. No part of this publication may b
3、e reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE.TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada)Tel: +1 724-776-4970 (outside USA)Fax
4、: 724-776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedbackon this Technical Report, please visithttp:/www.sae.org/technical/standards/AMS2750EAEROSPACEMATERIALSPECIFICATIONAMS2750 REV. EIssued 1980-04Revised 2012-07Superseding AMS2750D(R)
5、PyrometryRATIONALE5 year update and review of specification with reorganization to improve access. Technical changes resolve issues determined in usage. Changes are extensive and not marked.CONTENTS1. SCOPE 32. APPLICABLE DOCUMENTS 3 2.1 ASTM Publications 3 2.2 Definitions 3 3. TECHNICAL REQUIREMENT
6、S 8 3.1 Temperature Sensors . 8 3.2 Instrumentation (See Tables 3, 4, and 5) 12 3.3 Thermal Processing Equipment:. 16 3.4 System Accuracy Tests (SATs) 18 3.5 Furnace Temperature Uniformity Surveys (TUS) 23 3.6 Laboratory Furnaces . 33 3.7 Records. 33 3.8 Rounding. 33 4. QUALITY ASSURANCE PROVISIONS
7、33 4.1 Responsibility for Inspection 33 5. PREPARATION FOR DELIVERY . 42 6. ACKNOWLEDGEMENT . 42 7. REJECTIONS . 42 8. NOTES 43 -,-,-SAE AMS2750E Page 2 of 43FIGURE 1 REUSE AND RECALIBRATION OF TEST AND LOAD SENSORS. 13 FIGURE 2 FURNACE CLASS UNIFORMITY RANGES 16 FIGURE 3 INSTRUMENTATION TYPE REQUIR
8、EMENTS . 17 FIGURE 4 MINIMUM SENSORS REQUIRED PER ZONE 18 FIGURE 5 ALLOWABLE COMBINATIONS OF RESIDENT SAT SENSOR WITH SENSOR BEING TESTED FOR TEMPERATURES OVER 500 F (260 C) . 19 FIGURE 6 SAT CALCULATION EXAMPLES. 21 TABLE 1 SENSORS AND SENSOR CALIBRATION. 34 TABLE 2 THERMOCOUPLES AND EXTENSION WIRE
9、 35 TABLE 3 INSTRUMENTS AND INSTRUMENT CALIBRATION 36 TABLE 4 RESOLUTION REQUIREMENTS FOR CHART RECORDERS. 38 TABLE 5 PROCESS RECORDER PRINT AND CHART SPEEDS 38 TABLE 6 PARTS FURNACE CLASS, INSTRUMENT TYPE, AND SAT INTERVAL. 39 TABLE 7 RAW MATERIAL FURNACE CLASS, INSTRUMENT TYPE, AND SAT INTERVAL .
10、40 TABLE 8 PARTS FURNACE CLASS, INSTRUMENT TYPE, AND TUS INTERVAL 41 TABLE 9 RAW MATERIAL FURNACE CLASS, INSTRUMENT TYPE, AND TUS INTERVAL. 41 TABLE 10 PERMITTED CALIBRATION/TEST INTERVAL EXTENSION 42 TABLE 11 NUMBER OF TUS SENSORS REQUIRED 42 -,-,-SAE AMS2750E Page 3 of 431. SCOPE1.1 This specifica
11、tion covers pyrometric requirements for thermal processing equipment used for heat treatment. It covers temperature sensors, instrumentation, thermal processing equipment, system accuracy tests, and temperature uniformity surveys. These are necessary to ensure that parts or raw materials are heat tr
12、eated in accordance with the applicable specification(s).1.2 This specification is not applicable to heating, or to intermediate thermal processing unless specifically referenced by a material or process specification.1.3 This specification applies to laboratory furnaces to the extent specified in 3
13、.6.2. APPLICABLE DOCUMENTSThe issue of the following documents in effect on the date of the purchase order forms a part of this specification to the extent specified herein. The supplier may work to a subsequent revision of a document unless a specific document issue is specified. When the reference
14、d document has been canceled and no superseding document has been specified, the last published issue of that document shall apply.2.1 ASTM PublicationsAvailable from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959,Tel: 610-832-9585, www.astm.org.ASTM E 29
15、Standard Practice for Using Significant Digits in Test Data to Determine Conformance with SpecificationsASTM E 207 Standard Test Method for Thermal EMF Test of Single Thermoelement Materials by Comparison with a Reference Thermoelement of Similar EMF-Temperature PropertiesASTM E 220 Standard Test Me
16、thod for Calibration of Thermocouples by Comparison TechniquesASTM E 230 Standard Specification and Temperature-Electromotive Force (EMF) Tables for Standardized ThermocouplesASTM E 608 Standard Specification for Mineral-Insulated, Metal-Sheathed Base Metal ThermocouplesASTM E 1129 Standard Specific
17、ation for Thermocouple ConnectorsASTM MNL 7 Manual on Presentation of Data and Control Chart AnalysisASTM MNL 12 Manual on the Use of Thermocouples in Temperature Measurement2.2 DefinitionsTerms used in AMS are clarified in ARP1917 and as follows:2.2.1 ACCURACY: The maximum deviation of the instrume
18、ntation being tested from the corrected readings of a traceable standard.2.2.2 BASE METAL THERMOCOUPLE: Thermocouple whose thermoelements are composed primarily of base metals and their alloys. Examples of base metal thermocouples include E, J, K, N, and T.2.2.3 BIMONTHLY: In the context of this doc
19、ument, bimonthly is equal to once every two months.2.2.4 BIWEEKLY: In the context of this document, biweekly is equal to once every two weeks.-,-,-SAE AMS2750E Page 4 of 432.2.5 CALIBRATION: The process of adjusting an instrument or compiling a deviation chart so its reading may be correlated to the
20、 actual value being measured.2.2.6 CONTINUOUS FURNACE: A furnace where product is conveyed continuously from the charge area to thedischarge area.2.2.7 CONTROL INSTRUMENT: An instrument connected to a sensor and used to control the temperature of process equipment (including quench baths and refrige
21、ration equipment). The instrument may or may not also record temperature.2.2.8 CONTROL SENSOR: A sensor connected to the furnace temperature controller, which may or may not be recording.2.2.9 CONTROL ZONE OR FURNACE CONTROL ZONE: A portion of the working zone in thermal processing equipment having
22、a separate sensor/instrument/heat input or output mechanism to control its temperature. This portion of a furnace is independently controlled.2.2.10 CONTROLLED TEMPERATURE LIQUID BATH: A furnace containing a liquid that is heated to the desired heat treat temperature. Product is normally immersed in
23、 the liquid.2.2.11 CORRECTION FACTOR: The number of degrees, determined from the most recent calibration that must be added to, or subtracted from, the temperature reading of a sensor, or an instrument, or a combination thereof (system) to obtain true temperature. The correction factors of sensors a
24、nd instruments are usually kept separately and added together algebraically when a combination is used.2.2.12 DATA ACQUISITION SYSTEM: An instrument system used to automatically collect and store process data as an electronic record.2.2.13 DEAD BAND: The range within which the temperature input can
25、be altered upscale and downscale without registering a change on the instrumentation.2.2.14 DEVIATION: In the context of this document, the difference between the uncorrected indicated temperature and the true temperature.2.2.15 DIGITAL INSTRUMENT: An instrument that presents process measurements in
26、 a digital (numeric) display format. Typical examples are mechanical recorders with digital displays, digital indicators, controllers with digital displays, etc. In the case of a recorder with digital temperature display and a recorder trace (line) the record (recorder trace) is analog while the dis
27、play is digital. A recorder trace on a paper chart is an analog record. 2.2.16 ELECTRONIC RECORD: Any combination of text, graphics, data, audio, pictorial, or other information representation in digital form that is created, modified, maintained, archived, retrieved, or distributed by a computer sy
28、stem.2.2.17 ELAPSED USAGE TIME: Number of calendar days from the first use of a sensor, (regardless of the number of cycles of use). 2.2.18 EXPENDABLE THERMOCOUPLES: Thermocouples made of fabric or plastic covered wire. The wire is provided in coils or on spools. Insulation usually consists of glass
29、 braid, or ceramic fiber cloth on each conductor plus glass braid overall. 2.2.19 FAILURE OF SURVEY THERMOCOUPLE: Obviously incorrect or erratic activity of a survey thermocouple indicated by extreme high readings, extreme low readings, and/or erratic changes in readings not reflected by other senso
30、rs.2.2.20 FIELD TEST INSTRUMENT: An instrument that is portable, that meets the requirements of Table 3, has calibration traceable to secondary equipment or better and is used to conduct on-site tests of thermal processing equipment.-,-,-SAE AMS2750E Page 5 of 432.2.21 FLUIDIZED BED FURNACE: A furna
31、ce that contains a medium that becomes suspended or fluidized due to atmosphere gas or products of combustion passing upward through the medium. Product is normally immersed in the fluidized medium.2.2.22 FURNACE: Equipment used for the thermal processing of materials and parts. The term furnace inc
32、ludes ovens.2.2.23 GROUNDED JUNCTION: A sheathed thermocouple having the hot junction (measurement junction) end fused or welded to the end closure of the protective sheath.2.2.24 HEAT SINK: A mass of material equivalent to the heat transfer characteristics of the thinnest section of the part being
33、heat-treated. Heat sinks may be used during TUS (3.5.10.1) and during production (3.3.5).2.2.25 INTERVAL: The calendar time between 2 tests or calibrations. Examples include: week or weekly requires the due date is the same day in the following week a span of 7 calendar days; month or monthly to ind
34、icate the next test occurs on the same numerical day in the following month. If the monthly test is performed on the 31st day of a month followed by a month with 30 days, the due date is the last day of the following month (similar for tests on January 29-31 the due date is the last day of the follo
35、wing month. Same definitions apply to the bi-weekly, quarterly, semiannual and annual intervals.2.2.26 LABORATORY FURNACE: A furnace used only for determining response to heat treatment as required by material specifications.2.2.27 LOAD SENSORS: Sensors that are attached to or in contact with produc
36、tion material, a representation of production material, or are buried in the load of production material and which supply temperature data of the production material to process instrumentation.2.2.28 MAXIMUM PERMITTED ERROR: A tolerance band for the thermal electric response expressed in degrees or
37、percentages. Maximum permitted error provides a tolerance within which various types of thermocouples must conform to standard thermocouple reference tables.2.2.29 MATERIAL PRODUCER: The manufacturer that produces a product in accordance with a material specification that may require by reference co
38、nformance to a heat treat specification. Casting, extrusion and forging manufacturers and their approved vendors are considered material producers. Warehouses, distributors, or similar organizations are not considered material producers.2.2.30 MEASURING JUNCTION: That area of a thermocouple joined t
39、ogether to complete a measurement circuit, which is used to measure an unknown temperature. Also called the hot junction.2.2.31 MONITORING INSTRUMENT: An instrument connected to a controlling, monitoring, load or recording sensor that indicates process equipment temperature. Examples are an indicati
40、ng device, chart recorder, electronic data recorder or a data acquisition system.2.2.32 MONITORING SENSOR: A sensor connected to the monitoring instrument.2.2.33 NOBLE METAL THERMOCOUPLE: Thermocouple whose thermoelements are composed primarily of noble metals (e.g., platinum/platinum-rhodium) and t
41、heir alloys. Examples of noble metal thermocouples include types R, S and B.2.2.34 NONEXPENDABLE THERMOCOUPLES: Thermocouples that are not covered with fabric or plastic insulations. One type consists of ceramic insulators over bare thermocouple wire, sometimes inserted in a tube for stability and p
42、rotection. A second type consists of a combination of thermocouple wires, mineral insulation, and a protecting metal sheath compacted into a small diameter. The thermocouple thus constructed is protected, flexible and, within the temperature limits of the sheath material, may be used many times with
43、out insulation breakdown. This type of thermocouple, conforming to ASTM E 608, is available under many trade names.2.2.35 OVER-TEMPERATURE INSTRUMENTATION: A separate sensor and instrument combination installed in the furnace, which is used to monitor any over-temperature occurrence and generate an
44、alarm and/or cut back or shut down heat input. The purpose for this control is to protect material and/or the furnace from overheating.-,-,-SAE AMS2750E Page 6 of 432.2.36 PARTS HEAT TREATMENT: Heat treatment by a source other than the raw material producer. Product is tested to the requirements of
45、the heat treat processing specification or to selected requirements of other specifications.2.2.37 PREVENTIVE MAINTENANCE PROGRAM or PM PROGRAM: A program for evaluating, taking corrective action as required, and documenting the condition of items that have potential to adversely affect furnace temp
46、erature uniformity. Frequency of PM checks is established based on experience to ensure that no major problems occur between PMs.2.2.38 PRIMARY TEST SENSOR: Sensor with calibration directly traceable to a reference standard. Normally used to calibrate secondary test sensors.2.2.39 PROCESS CHART RECO
47、RDER: See Recording Instrument definition.2.2.40 PRIMARY TEST INSTRUMENT: An instrument that is calibrated directly against instruments calibrated by NIST or equivalent national standard. Normally used to calibrate secondary instrumentation.2.2.41 QUALIFIED OPERATING TEMPERATURE RANGE: The temperatu
48、re range of thermal processing equipment where temperature uniformity has been tested and found to be within required tolerances as specified in 3.3. 2.2.42 QUALIFIED WORK ZONE: The defined portion of a furnace volume where temperature variation conforms to the required uniformity tolerance.2.2.43 QUALITY ORGANIZATION APPROVAL: Documented process for review and acceptance/rejection of a report or test which also defines any delegation of this approval. 2.2.44 QUENCH SYSTEM: A system that facilitates rapid cooling,
