1、 ISA-TR52.00.01-2006 Recommended Environments for Standards Laboratories Approved 29 December 2006 ISA-TR52.00.01 Recommended Environments for Standards Laboratories ISBN: 978-1-55617-977-8 Copyright 2006 by ISA The Instrumentation, Systems, and Automation Society. All rights reserved. Not for resal
2、e. Printed in the United States of America. 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 the Publisher. ISA 67 Alexander
3、Drive P.O. Box 12277 Research Triangle Park, North Carolina 27709 - 3 - ISA-TR52.00.01-2006 Copyright 2006 ISA. All rights reserved. Preface This preface, as well as all footnotes and annexes, is included for information purposes and is not part of ISA-TR52.00.01-2006. This document has been prepare
4、d as part of the service of ISA the Instrumentation, Systems, and Automation Society toward a goal of uniformity in the field of instrumentation. To be of real value, this document should not be static but should be subject to periodic review. Toward this end, the Society welcomes all comments and c
5、riticisms and asks that they be addressed to the Secretary, Standards and Practices Board; ISA; 67 Alexander Drive; P. O. Box 12277; Research Triangle Park, NC 27709; Telephone (919) 549-8411; Fax (919) 549-8288; E-mail: standardsisa.org. This project began with Task Force No.1 on Environmental Stan
6、dards as organized by the Measurement Standards Division in 1959. A report was published in the February 1961 issue of the ISA Journal, entitled “Recommended Environments for Standards Laboratories.“ In 1962 the Measurement Standards Instrumentation Division organized the F-6 Environmental Committee
7、. The Committees report was published in the October 1964 issue of ISA Transactions, entitled “Recommended Environments for Standards Laboratories.“ The committee known as the RP 52 Committee on Recommended Environments for Standards Laboratories was organized by the Metrology Division in 1966. This
8、 committee conducted a panel discussion meeting at the 23rd Annual ISA Conference (1968) in New York City. The purpose was to review the 1964 Recommendations and to elicit new information from the audience on experience gained from environmental control of standards laboratories. From a resume of th
9、is panel discussion it was possible for the committee members to formulate a revision of the 1964 Recommendations in light of new information. As an additional step, a reedited version of the panel discussion was sent to 29 members of the National Conference of Standards Laboratories (NCSL) in order
10、 to gain further information. Selection for this survey was made from among the total membership in NCSL on the basis of extended experience with operation of a standards laboratory where environmental control was a factor of concern and interest. From responses of a portion of the 29 members select
11、ed, it was possible for the committee to have additional information at hand as an aid in revising the 1964 Recommendations. The result of this somewhat lengthy process of revision was the original ISA-RP52.1-1975 document. The SP52 committee has updated the existing references within this document
12、and also added references to NSTL RP-14, Guide to Selecting Standards-Laboratory Environments, where appropriate in this version published as a technical report. The ISA Standards and Practices Department is aware of the growing need for attention to the metric system of units in general, and the In
13、ternational System of Units (SI) in particular, in the preparation of instrumentation standards. The Department is further aware of the benefits to USA users of ISA standards of incorporating suitable references to the SI (and the metric system) in their business and professional dealings with other
14、 countries. Toward this end, this Department will endeavor to introduce SI-acceptable metric units in all new and revised standards, recommended practices, and technical reports to the greatest extent possible. Standard for Use of the International System of Units (SI): The Modern Metric System, pub
15、lished by the American Society for Testing also, “An Echelon of Standards,” Chapter 2 pp. 10-13, of Basic Electronic Instrument Handbook, Clyde F. Coombs, Jr., Editor, McGraw-Hill Book Co., New York, 1972. ISA-TR52.00.01-2006 - 14 - Copyright 2006 ISA. All rights reserved. 4.6 Relative humidity See
16、also NCSL RP-14, Section 6. 4.6.1 Applicable laboratory: Dimensional Requirements: Types I and II: 45%, maximum relative humidity, (around a regulated temperature of 20C). 4.6.2 Applicable laboratory: All other than dimensional Requirements: Type I: 35-55% around a regulated temperature of 23C Type
17、II: 20-55% around a regulated temperature of 23C 4.7 Temperature See also NCSL RP-14, Section 3. 4.7.1 Applicable laboratory: Dimensional and optical Requirements: Type I: 20 0.3C 20 0.1C at gaging point Type II: 20 1C 20 0.3C at gaging point 4.7.2 Applicable laboratory: Temperature, acceleration, d
18、c, low-frequency, and pressure-vacuum Requirements: Type I: 23 1C Type II: 23 1.5C 4.7.3 Applicable laboratory: Flow, force, high-frequency, and microwave Requirements: Type I: 23 1.5C Type II: 23 1.5C 4.8 Vibration See also NCSL RP-14, Section 4. 4.8.1 Applicable laboratory: Dimensional, optical, p
19、ressure-vacuum, acceleration, force, and mass - 15 - ISA-TR52.00.01-2006 Copyright 2006 ISA. All rights reserved. Requirements: Types I and II: 0.25 micrometer, (250 nm), (10 micro-inches) maximum displacement amplitude from 0.1 Hz to 30 Hz, 0.001g maximum from 30 Hz to 200 Hz. 4.8.2 Applicable labo
20、ratory: Temperature, flow, dc, low-frequency, high-frequency, and microwave Requirements: Types I and II: No specific requirements. 4.9 Voltage regulation 4.9.1 Applicable laboratory: All types employing electronic measuring instruments Requirements: Types I and II: Maximum change from average volta
21、ge less than 0.1%, with consideration of holding transients at a minimum. Total rms value of all harmonics should not exceed 5% of the rms value of the fundamental from no load to full load of regulator.ISA-TR52.00.01-2006 - 16 - Copyright 2006 ISA. All rights reserved. Annex A Comments and referenc
22、e material A.1 Acoustic noise A.1.1 Much has been written on both the objective and subjective observations of acoustic noise and the effect of noise on humans. With increased knowledge, there is concern about exposure to high sound levels that may be injurious to people. Although no harmful effects
23、 of a lasting nature occur from distracting noises at the sound levels of common experience, these noises can be psychologically harmful without the subject being aware of the effect. Such considerations must be kept in mind in the design of laboratories. Because there is little information in the l
24、iterature on noise level surveys in specialized laboratory areas, the best criteria that can be advanced are the noise levels commonly experienced for private offices. It is reasonable to expect that operations in a standards laboratory should be carried out in an environment that is as conducive to
25、 concentration and freedom from distracting noises as one would find in an executive office with quiet surroundings. There is a considerable amount of information available on office environments in the literature. Because of more refined methods of measurement, there has been a trend in recent year
26、s to recommend even lower noise levels. In the earlier years of measurement and evaluation, the noise tolerance usually specified for a private office was that it should be no greater than 45 dB measured on a sound level meter. The acceptable noise level for private offices is 40 to 45 dB,(1)(8)as m
27、easured on a sound level meter using the A, or 40-dB weighting network. Extensive investigations have indicated that the problems of noise measurement and the evaluation of loudness and annoyance are considerably more complex than they appeared to be forty years ago. New methods of measurement techn
28、iques have been developed with more complex methods of evaluation. Investigators in this area have been Stevens,(3, 4)Beranek,(2, 5)Kryter, (6)also Zwicker and others. For an evaluation and references to these investigations see Corliss and Winzer,(7)Young,(8)and Ohme.(9)Peterson and Gross(10) have
29、consolidated much of this information into a handbook. In view of the complexity of loudness evaluation, it recommended that noise measurement in laboratory areas be made by the relatively simple sound level meter technique using the A or 40-dB weighting network. The measurement should be made with
30、a meter that meets the ANSI SI.4- 1983 (R1997) American National Standard Specification for Sound Level Meters. The size of the room, degree of sound absorption, the noise produced by the air conditioning system as well as by the laboratory equipment, and the number of people in the area, will be de
31、termining factors for sound levels under working conditions. The sound level can be high, on occasion, due to normal work activity and noise from laboratory and office equipment. Attainment of a low sound level will come mainly from a relatively low noise level of the general environment and, to a c
32、onsiderable degree, can be partially achieved by sound-insulated walls, floors, and ceilings. The use of sound absorption materials on interior surfaces is recommended to obtain more pleasant surroundings by reducing reverberation effects and the harsh effects of highly reflecting surfaces. It is ve
33、ry important to select a material that does not shed particles for use as a sound absorber in the laboratory area. A.1.2 Reference material 1) Knudsen, V. O., and C. M. Harris, Acoustical Designing in Architecture, John Wiley, New York, 1950. 2) Beranek, Leo L., “Criteria for Office Quieting Based o
34、n Questionnaire Rating Studies,“ J. Acoust. Soc. Am. Vol. 28, No. 5, pp. 833-852, September 1956. 3) Stevens, S. S., “Calculation of the Loudness of Complex Noise,“ J. Acoust. Soc. Am. Vol. 28, No. 5, pp. 807-832, September 1956. - 17 - ISA-TR52.00.01-2006 Copyright 2006 ISA. All rights reserved. 4)
35、 Stevens, S. S., “Calculating Loudness,“ Noise Control, Vol. 3, No. 5, pp. 11-22, September 1957. 5) Beranek, Leo L., “Revised Criteria for Noise in Buildings,“ Noise Control, Vol. 3, No. 1, pp. 19-27, January 1957. 6) Kryter, Karl D., The Effects of Noise on Man, Academic Press, New York, 1970. 7)
36、Corliss, Edith L. R. and George E. Winzer, “Study of Methods for Estimating Loudness,“ J. Acoust. Soc. Am. Vol. 38, No. 3, pp. 424-428, September 1965. 8) Young, Robert W., “Single-Number Criteria for Room Noise,“ J. Acoust. Soc. Am. Vol. 36, No. 2, pp. 289-295, February 1967. 9) Ohme, Wolfgang E.,
37、“Loudness Evaluation,“ Hewlett-Packard J. Vol. 19, No. 3, pp. 2-11, November 1967. 10) Peterson, A. P. G. and E. E. Gross, Handbook of Noise Measurement, General Radio Company, West Concord, Mass. 7th Edition, 1972. 11) See Chapter 12, “Sound and Vibration,“ ASHRAE Guide and Data Book - Systems, Ame
38、rican Society of Heating, Refrigeration and Air Conditioning Engineers, New York, 1970. A.2 Dust particle count A.2.1 A judgement of how much dust can be tolerated is not easy to determine on a quantitative basis. Recommendations are based mainly on good housekeeping considerations. This is the best
39、 single practice to avoid the adverse effects caused by dusty environments. In low-frequency measurements, dust accumulation on insulating or conducting surfaces can influence measurements. Many standard laboratory instruments utilize exposed contact construction making repeated cleaning necessary i
40、n a dust-laden area. The dust contamination of oil baths required in standards laboratory measurements must be considered. Dust can promote rust and corrosion and contaminate standard samples and measurements involving fluids in flow measurements. In open-air systems utilizing mercury reservoirs or
41、columns, dust can increase errors in pressure-vacuum measurements. The use of mechanical and/or electrostatic traps and filters can help regulate dust. Dust control is also important in laboratories where dead-weight testers are used. The accuracy of a dead-weight gage can be reduced due to airborne
42、 particles, such as skin flakes, clothing fibers, and hair. Filters for incoming air can be constructed of oil-coated glass fibers or fine metallic ribbon that can be cleaned and re-oiled (1)or disposed of periodically. High Efficiency Particulate Air (HEPA) filter units are used to clean rooms and
43、for other applications where a high degree of filter efficiency is required or desirable.(2)In low-humidity areas, washing the incoming air to add moisture will tend to reduce the dust content. Pressurization of the laboratory environment will reduce the entry of dust-laden air (see laboratory air p
44、ressure clause). A.2.2 Numerous methods of dust monitoring or dust counting, are described in the literature, some relatively simple, others relatively complex and with automatic readout. One of the least expensive is the dry-slide technique.(3)In this method, a projection microscope enlarges the co
45、ntents of a glass slide which has been exposed to the air in a particular area of the laboratory for a definite period of time. The operator counts the number of particles in random sample fields of a gridded screen and measures their size on the projection microscope graticule. A slightly more comp
46、lex and expensive procedure for particle size 5 m and larger involves microscope counting of particles collected on a membrane filter through which a known volume of air has been drawn. The procedure is required in Federal Standard No. 209(4)and detailed operating techniques for sampling in clean ro
47、oms and other areas are available in ASTM-F-ISA-TR52.00.01-2006 - 18 - Copyright 2006 ISA. All rights reserved. 25-68(5)and SAE-ARP-743(6). A Department of Army Technical Bulletin(7)specifies a modified program similar to that specified in references (5) and (6) which is considered suitable for use
48、in calibration laboratories equivalent to Echelon II, Type II. This program gives some measure of assurance that housekeeping, filter maintenance, etc., is adequate without the costly and time consuming daily routine of clean-room monitoring. The design criteria of a Class II clean room as outlined
49、in Air Force T.O. 00-25-203 and the operating criteria of a Class II clean room as outlined in Air Force T.O. 33-1-14 specify dust counts. The latter, published in December 1962, states that a maximum of 85 x 103particles between 0.3 and 10 m and a maximum of 15 x 103particles larger than 10 m per cubic foot will be tolerated. The new superseding D.O.D. statement, MIL-C-45622A, paragraph 3.2.2. says that measuring and test equipment and measurement standards shall be calibrated and used in an environment controlled to the extent necessary to assure continued meas
