1、 SURFACE VEHICLE STANDARD J2970 MAR2015 Issued 2012-07 Revised 2015-03 Superseding J2970 JUL2012 Minimum Performance Requirements for Non-Refrigerant Tracer Gasses and Electronic Tracer Gas Leak Detectors RATIONALE This standard is being updated to modify the requirements when the tracer gas is sign
2、ificantly lighter than air. The Contaminated Atmosphere test is not required for tracer gases with a molecular weight of 20 or lower. Tracer gases with a molecular weight of 20 or lower will diffuse rapidly into the ambient atmosphere and will therefore not be a contaminant. 1. SCOPE This standard p
3、rovides the testing and functional requirements guidance necessary for a leak detection device that uses any non-A/C refrigerant tracer gas, such as helium or a nitrogen-hydrogen blend, to provide functional performance equivalent to a refrigerant electronic leak detector. It explains how a non- ref
4、rigerant leak detectors calibration can be established to provide levels of detection equal to electronic leak detectors that meet SAE J2791 for R-134a and SAE J2913 for R-1234yf. 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this specification to the extent specif
5、ied herein. Unless otherwise indicated, the latest issue of SAE publications shall apply. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. SAE J2197 Hfc-13
6、4a (R-134a) Service Hose Fittings for Automotive Air-Conditioning Service Equipment SAE J2888 R-1234yf Service Hose, Fittings and Couplers for Mobile Refrigerant Systems Service Equipment SAE J2791 HFC-134a Refrigerant Electronic Leak Detectors, Minimum Performance Criteria SAE J2913 R-1234yf HFO-12
7、34yf Refrigerant Electronic Leak Detectors, Minimum Performance Criteria _ 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 suitabilit
8、y for any particular use, including any patent infringement arising therefrom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions
9、. Copyright 2015 SAE International All rights reserved. No part of this publication may be 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 DOCU
10、MENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J2970_20
11、1503 SAE INTERNATIONAL J2970 Revised MAR2015 Page 2 of 15 SAE J2670 Stability and Compatibility Criteria for Additives and Flushing Materials Intended for Aftermarket Use in R-134a (HFC-134a) and R-1234yf (HFO-1234yf) Vehicle Air-Conditioning Systems SAE J2911 Procedure for Certification that Requir
12、ements for Mobile Air Conditioning System Components, Service Equipment and Service Technician Training Meet SAE J Standards 3. GENERAL DESCRIPTION AND OPERATING INSTRUCTIONS 3.1 The tracer gas detector shall be suitable for use in safely detecting the tracer gas following recovery of refrigerant fr
13、om the system with equipment that meets SAE J2788 (R-134a) or SAE J2810 (R-134a), SAE J2843 (R-1234yf), SAE J2851 (contaminated systems) or other recovery equipment meeting SAE standards published after this standard. 3.2 The tracer gas shall be suitable for use at temperatures of 15-49 C. (59 to 12
14、0 F.) and have the following characteristics: 3.2.1 It shall meet the commodity specifications of the Compressed Gas Association. 3.2.2 It shall be non-flammable. 3.2.3 It shall be removable from the mobile air conditioning system with ordinary A/C shop equipment, and/or self-release from the system
15、, leaving no residue, in less than 30 minutes. (Note: the tracer gas should not be recovered into the tank of SAE J2788 or SAE J2843 Recovery/Recycling/Recharging equipment. When releasing, care should be taken so the background level of the tracer gas is not increased which may impact further leak
16、detection.) 3.2.4 The pressure required for proper leak detection shall be less than 1.1 MPa (160 psig). 3.2.5 The safety and chemical compatibility of the tracer gas must cover the possibility of a mixture of up to 20% of the system refrigerant from incomplete recovery. Reference SAE J2670 for exam
17、ple test methods. The method of demonstrating compatibility with R-1234yf and R-134a is left to the discretion of the manufacturer/marketer or the test lab, but shall be described with supporting data, as an addendum to the comments section. 3.3 The tracer gas detector shall be tested to meet the pe
18、rformance specifications of this standard by an independent testing facility as defined in SAE J2911, and in accordance with the procedures set forth in SAE J2911. The independent testing facility shall maintain all documentation related to its testing, including calibration and maintenance data for
19、 its equipment, for a period of five years following the final production test of the specific detector. 3.3.1 The manufacturer may state certification of compliance with this Standard (including use of any labeling) only after meeting the requirements in SAE J2911 “Procedure for Certification That
20、Requirements for Mobile Air Conditioning System Components, Service Equipment and Service Technicians Meet SAE J Standards”. See Appendix B. 3.4 If it complies, the detector shall carry a label that states “Design certified by (name of testing laboratory) to meet SAE J2970 with (type of tracer gas,
21、such as 95% nitrogen/5% hydrogen) at (tracer gas test pressure)“ with lettering in bold face type at least 3 mm high. 3.5 If it fails to comply, the detector may be retested subject to the limits of Section 11. If a detector fails beyond the retest limits of Section 11, it shall be retested only aft
22、er the manufacturer/marketer has documented design or process changes made to correct the failure and provided this data to the testing laboratory. A detector must pass the procedures in Sections 7, 8. A failure in either or both of those sections requires a complete retest. The detector also must m
23、eet the requirements of Section 10, passing the no-false-triggering requirement for transmission oil and engine oil (Nos. 13 and 14) and clearing within 20 s after a permitted false-trigger. 3.6 The tracer gas detector shall be suitable for use in an automotive service garage and operate in ambient
24、temperatures of 15 to 49 C (59 to 120 F). SAE INTERNATIONAL J2970 Revised MAR2015 Page 3 of 15 3.7 The tracer gas detector shall be capable of identifying leak rates equivalent to 4 g/year (0.15 oz/year) and 7 g/year (0.25 oz/year) of refrigerant R-134a or R-1234yf when tested using calibrated leak
25、standards certified for both the refrigerant and the tracer gas. At the discretion of the manufacturer, the tracer gas detector may be capable of identifying a leak rate equivalent to 14 g/year (0.5 oz/year). The equivalent leak rates shall be determined at the refrigerant vapor pressure at 20 to 22
26、 C (68 to 72 F) and the specified test pressure for proper leak detection for the tracer gas. The selection of the base refrigerant, R-134a or R-1234yf, is at the discretion of the manufacturer/marketer or the test lab. When a numeric leak rate is indicated it shall be displayed in g/yr of refrigera
27、nt equivalent. 3.8 Other equipment requirements (if included with the detector) 3.8.1 All couplings for attachment to MAC systems with R-134a shall meet SAE Standard J2197. 3.8.2 All couplings for attachment to MAC systems with R-1234yf shall meet SAE Standard J2888. 4. WHAT SHALL ACCOMPANY THE DETE
28、CTOR 4.1 The manufacturer/marketing company shall provide operating instructions for the detector that cover tracer gas specification and pressure needed for proper leak detection, tracer gas installation and removal, detector calibration, normal usage, trouble shooting, and maintenance, including r
29、eplacement of any sensors, filters or power supply. 4.2 Tools, adapters and needed adjustment and calibration devices (including calibration and/or reference bottles) for the detector must be included with the detector. 4.3 The manufacturer/marketing company shall provide all needed safety informati
30、on and labeling. 4.4 The manufacturer/marketing company shall provide the Section 10 list of all common under hood chemicals that may affect the operation of an electronic leak detector and indicate by Y, if their detectors will false-trigger from exposure to each of the chemicals on the list, or N
31、if it will not indicate a false-trigger. 4.5 The resistance to false triggering shall be based on the test procedures described in Section 10. False triggering is defined as the detector making the same or similar indication (sound and/or light) as if it detected a tracer gas leak. 5. REQUIRED BASIC
32、 FUNCTIONS 5.1 The detector may self-calibrate or require manual calibration, but once calibrated for an operation, it must hold that calibration for a time sufficient to perform the operations described in Sections 7 and 8 (including 8.1 to 8.6). This does not preclude automatic recalibration for a
33、 probe that has been inserted into a contaminated atmosphere (as per Section 8), readjustment of sensitivity by operator selection, or an audible-and-or-visual warning of a condition beyond the operating scope of its design. The latter must be obviously different from the indication of a leak, altho
34、ugh the same functional trigger may be used. Example: a steady indicator light vs. a flashing indicator light. 5.2 The detector shall have two sensitivity positions, designated “high” and “normal” equivalent to the 4, and 7 g/yr leakage rates of refrigerant (SAE J2791 or SAE J2913). At the discretio
35、n of the manufacturer, the detector may have an additional sensitivity setting designated “low“ equivalent to the 14 g/yr leakage rate of refrigerant (SAE J2791 or SAE J2913). 5.3 The detector must demonstrate automotive garage durability by continuing to function normally after being dropped 1.2 m
36、(4.0 ft) to a hard surface, such as a concrete floor, four times. This test may be performed with the detector in a protective caddy, provided the caddy is a standard part of the basic detector kit, and does not affect in-shop use of the detector, or testing of the detector under all procedures in S
37、ections 7, 8, 9 and 10. SAE INTERNATIONAL J2970 Revised MAR2015 Page 4 of 15 5.4 The detector must demonstrate automotive garage durability by continuing to function normally after: the probe tip has been submerged to a depth of 6 mm (0.25 in) in a pan of water and drawn through the water at a rate
38、of 75 mm (3 in) per second for two seconds and then, after wiping clean and performing any other cleaning/maintenance prescribed by the manufacturer in its operating instructions manual, including but not limited to a sensor replacement or filter change. 6. LEAK DETECTION TEST EQUIPMENT 6.1 The test
39、ing shall be performed with the probe in a 610 mm (2 ft) cube clear sealed chamber as described in the appendix, figures A1 and A2. A chamber built to conform to SAE J2791/SAE J2913 is suitable. 6.1.1 Illustrations and details of the chamber are described in the Appendix A. A vertical wall of the ch
40、amber shall have a horizontal slot 200 mm (8 in) or wider, and large enough for a probe from an externally-mounted detector to go through. The slot opening shall be sealed with: 6.1.1.1 Overlapping strips of a rubber material that conforms sufficiently around the probe to maintain the specified leve
41、l of contaminated atmosphere, or 6.1.1.2 A butt-joint of conforming rubber seals with additional sealing from face seals on the detector probe neck that are in contact with the butt joint. 6.1.1.3 Any other slot sealing method that provides the chamber sealing required for Section 8. The rubber stri
42、ps and face seals may be lubricated to provide smooth movement of the probe and any surrounding brace as described in 6.2. 6.1.2 The chamber shall have an access door large enough to insert a calibrated leak standard, a cylindrical sleeve or round-hole access point for a gas-tight syringe and a buil
43、t-in mixing fan (120 V, 240 V or local voltage, approximately 68 m3/hr (40 cfm) to circulate an injection of a designated contaminated atmosphere gas to produce uniform distribution of injected gas for the contaminated atmosphere test. The chamber should have a provision for attaching a vacuum sourc
44、e (such as a small household vacuum motor) to permit rapid clearing of the chamber following a contaminated atmosphere test. The cylindrical sleeve or round-hole access shall include a sealing plug or other provision for sealing following use of the gas-tight syringe. 6.1.2.1 The designated contamin
45、ated atmosphere gas shall be the tracer gas, except as noted in Section 8 for tracer gases with a molecular weight of 20 or lower, which are exempted from the test. 6.1.3 The three (optionally four) calibrated leak standards used for the tests shall be calibrated per methods and instruments per the
46、National Institute of Standards and Technology, Washington, DC 20234 (or an equivalent government-recognized source for traceable standards if testing outside the USA), and the standards shall be rated accurate (have measurement uncertainty) to within 20%. The leak rates for these standards shall be
47、 in common units for R-134a or R-1234yf of 7 g/yr (0.25 oz/yr), 4 g/yr (0.15 oz/yr), 2.0 g/yr (0.0625 oz/yr) and optionally 14 g/yr (0.5 oz/yr), at the refrigerant vapor pressure at 20 to 22 C (68 to 72 F) and certified (calibrated with a certificate of calibration) for use with both the refrigerant
48、 and the tracer gas. These leak rates may be different from the leak rates with the tracer gas, as the objective is to determine the refrigerant leak rate, and provide an equivalency for evaluating the refrigeration system integrity. The leak standards shall be designed for connection to a supply of
49、 100% of the tracer gas or if a blend, 100% of the specified blend. If the tracer gas is heavier than air, the standards or their mounting locations in the chamber shall ensure the base of the standard is 75 mm (3 in) or more from the floor of the chamber. This is to provide a sufficient drop for the tracer gas coming from the leak standard o
