1、 Institute of Environmental Sciences and Technology Contamination Control Division IEST-RP-CC013.3 Recommended Practice 013.3 Calibration Procedures and Guidelines for Select Equipment Used in Testing Cleanrooms and Other Controlled Environments Arlington Place One 2340 S. Arlington Heights Road Arl
2、ington Heights, IL 60005 Phone: (847) 981-0100 Fax: (847) 981-4130 E-mail: informationiest.org Web: www.iest.org 2 IEST 2012 All rights reserved Institute of Environmental Sciences and Technology IEST-RP-CC013.3 This Recommended Practice is published by the Institute of Environmental Sciences and Te
3、chnology to advance the technical and engineering sciences. Use of this document is entirely voluntary, and determination of its applicability and suitability for any particular use is solely the responsibility of the user. Use of this Recommended Practice does not imply any warranty or endorsement
4、by IEST. This Recommended Practice was prepared by and is under the jurisdiction of Working Group 013 of the IEST Contamination Control Division. Copyright 2012 by the Institute of Environmental Sciences and Technology First printing, August 2012 ISBN 978-1-937280-04-8 PROPOSAL FOR IMPROVEMENT: The
5、Working Groups of the Institute of Environmental Sciences and Technology are continually working on improvements to their Recommended Practices and Reference Docu-ments. Suggestions from users of these documents are welcome. If you have a suggestion regarding this docu-ment, please use the online Pr
6、oposal for Improvement form found on the IEST website at www.iest.org. Institute of Environmental Sciences and Technology Arlington Place One 2340 S. Arlington Heights Road Arlington Heights, IL 60005 Phone: (847) 981-0100 Fax: (847) 981-4130 E-mail: informationiest.org Web: www.iest.org IEST-RP-CC0
7、13.3 Institute of Environmental Sciences and Technology IEST 2012 All rights reserved 3 Calibration Procedures and Guidelines for Select Equipment Used in Testing Cleanrooms and Other Controlled Environments IEST-RP-CC013.3 CONTENTS SECTION 1 SCOPE AND LIMITATIONS . 5 2 REFERENCES 5 3 TERMS AND DEFI
8、NITIONS . 6 4 BACKGROUND AND PURPOSE . 8 5 GENERAL PROCEDURES 8 6 AEROSOL GENERATORS 10 7 PHOTOMETERS 11 8 ANEMOMETERS . 15 9 AIRFLOW CAPTURE HOODS . 16 10 TEMPERATURE MEASUREMENT SYSTEMS AND DEVICES . 17 11 PRESSURE AND VACUUM GAUGES 21 12 POLYMER MICROSPHERE (PSL) GENERATORS 25 13 AEROSOL DILUTERS
9、 . 26 14 CONDENSATION NUCLEI COUNTERS 27 FIGURE 1 DETAILS OF A LASKIN NOZZLE. 10 2 SETUP FOR VERIFYING A LASKIN-NOZZLE-TYPE DOP GENERATOR. 10 3 100 G/L AEROSOL SOURCE 11 4 PRESSURE/VACUUM ACCURACY 23 5 VACUUM ACCURACY 24 6 PRESSURE ACCURACY USING A DEADWEIGHT TESTER STANDARD 24 7 RESTRICTION DILUTER
10、 . 26 8 AIRFLOW DILUTERS . 27 C1 TYPES OF WIND TUNNELS (FROM WIND TUNNELS OF NASA). . 31 4 IEST 2012 All rights reserved Institute of Environmental Sciences and Technology IEST-RP-CC013.3 TABLE 1 RECOMMENDED INITIAL CALIBRATION INTERVALS 8 D1 ACCURACY OF ICE BATHS. . 32 D2 THERMOCOUPLE (T/C) TYPE LE
11、TTER DESIGNATIONS 33 D3 RESISTANCE TEMPERATURE DEVICE (RTD) SENSORS 33 D4 “AS FOUND” UUT READINGS 34 APPENDIX A PROPER INSTRUMENT CARE PROTOCOL 29 B EXAMPLES OF PHOTOMETER TEST PROCEDURES . 30 C WIND TUNNELS 31 D TEMPERATURE MEASUREMENT SYSTEMS AND DEVICES . 32 E AIRFLOW DILUTION SETUP 10:1 EXAMPLE
12、35 F BIBLIOGRAPHY 36 IEST-RP-CC013.3 Institute of Environmental Sciences and Technology IEST 2012 All rights reserved 5 Institute of Environmental Sciences and Technology Contamination Control Division Recommended Practice 013.3 Calibration Procedures and Guidelines for Select Equipment Used in Test
13、ing Cleanrooms and Other Controlled Environments IEST-RP-CC013.3 1 SCOPE AND LIMITATIONS 1.1 Scope This Recommended Practice (RP) covers procedures for calibrating and verifying equipment used in char-acterizing cleanrooms and for determining intervals of calibration. The RP includes general procedu
14、res for calibrating aerosol generators, photometers, ane-mometers, airflow capture hoods, temperature meas-urement systems and devices, pressure and vacuum gauges, polymicrosphere (PSL) generators, aerosol diluters, and condensation nuclei counters. Where available, references for calibrating other
15、instruments are provided. 1.2 Limitations Future revisions of this document will include cali-bration procedures for additional instruments that re-quire procedures. NOTE: Testing in accordance with this RP may in-volve hazardous materials, operations, and equip-ment. This RP does not purport to add
16、ress all of the safety problems associated with the use of the docu-ment. It is the responsibility of the user to establish appropriate safety and health practices and to deter-mine the applicability of regulatory limitations prior to use of this RP. 2 REFERENCES The cited editions of the following
17、documents are in-corporated into this RP to the extent specified herein. Users are encouraged to investigate the possibility of applying the most recent editions of the references. 2.1 References and applicable documents ANSI/NCSL Z540.3: Requirements for the Calibra-tion of Measuring and Test Equip
18、ment. Echols, W.H. and J.A. Young. 1963. Studies of Portable Air-Operated Aerosol Generators. US Naval Research Laboratory (NRL) Report 5929. Washington, DC. IEST-RP-CC001.5: HEPA and ULPA Filters ISO 10012:2003 Measurement management systems Requirements for measurement processes and measuring equi
19、pment. 2.2 Sources and addresses IEST Institute of Environmental Sciences and Technology 2340 S. Arlington Heights Road Arlington Heights, Illinois 60005, USA Phone: 847-981-0100 Fax: 847-981-4130 www.iest.org 6 IEST 2012 All rights reserved Institute of Environmental Sciences and Technology IEST-RP
20、-CC013.3 ISO ISO 10012 available from: International Organization for Standardization (ISO) 1, ch. de la Voie-Creuse, Case postale 56 CH-1211 Geneva 20, Switzerland Phone: +41 22 749 01 11 Fax: +41 22 749 09 47 www.iso.org NCSL NCSL International 2995 Wilderness Place, Suite 107 Boulder, Colorado 80
21、301-5404, USA Phone: 303-440-3339 Fax: 303-440-3384 www.ncsli.org 3 TERMS AND DEFINITIONS The following terms have special meaning in this RP: accuracy The extent to which the value of a quantity indicated by an instrument under test agrees with the accepted value of the quantity. aerosol diluter A
22、device that reduces the particle concentration by a known dilution ratio of the device. The diluters typi-cally mix a known volume of sample air with a known volume of particle-free or filtered air to achieve dilu-tion. The ratio of the two volumes is the dilution ratio. aerosol diluter, restrictor
23、A device that reduces the particle concentration by impeding flow. Devices used for this purpose include but are not limited to hypodermic needle tubing, ca-pillary tubing, and very small orifices. aerosol generator An instrument for generating aerosol. Laskin nozzle type A system that uses a nozzle
24、 to generate a polydisperse aerosol from a liquid, such as dioctyl phthalate (DOP), that uses a source of compressed gas as shown in the Echols and Young study, NRL 5929. thermal polydisperse type A device that generates a polydisperse aerosol from a liquid such as DOP by means of an evaporation-con
25、densation process in the ab-sence of a controlled nucleation. The particle size distribution and mass mean diameter of an aerosol produced by a thermal generator are measurably smaller than those of an aerosol from a Laskin nozzle. aerosol photometer An instrument that measures the mass concentratio
26、n of an aerosol using the forward light scattering prin-ciple. At a minimum, the instrument should be capa-ble of measuring aerosol concentrations of 100 g/L or greater with a threshold sensitivity of at least 0.001 g/L. These parameters indicate the photometer has a sensitivity of 0.001%. airflow c
27、apture hood A volumetric airflow measuring device consisting of a fabric capture bag, support frame, and flow-sensing component providing a direct readout in cubic meters per hour (m3/hr) or cubic feet per minute (ft3/min). anemometer An instrument for measuring air velocity. rotating vane type An i
28、nstrument for measuring air velocity that contains an element that rotates in response to the airflow and converts the rotation to a velocity reading. thermoanemometer An instrument for measuring air velocity that contains an element heated by a regulated elec-tric source and cooled by the airflow.
29、A thermo-anemometer converts the cooling effect on the element to a velocity reading. as-found data The data showing the response of an instrument to known standards before the instrument is adjusted or calibrated. calibrate To compare the measurement of a standard or in-strument of unknown accuracy
30、 with another standard or instrument of known accuracy to detect, correlate, report, or minimize by adjustment any variation in the accuracy of the unknown standard or instrument. coincidence limit The aerosol concentration level where the presence of two or more particles in the sensing volume of t
31、he in-strument at the same time causes the instrument to in-terpret the combined signal erroneously as resulting from one larger particle. condensation nuclei counter (CNC) A device for counting aerosol particles. CNCs func-tion by saturating an aerosol sample with vapor, typi-cally alcohol or water
32、, and then condensing the vapor onto the particles. The particles grow by vapor depo-sition to a size such that the individual particles are easily detected by passing them through a focused la-ser light beam. Also called a condensation particle counter (CPC). IEST-RP-CC013.3 Institute of Environmen
33、tal Sciences and Technology IEST 2012 All rights reserved 7 condensation particle counter (CPC) See condensation nuclei counter (CNC) D50 The diameter of an aerosol particle that has a 50% counting efficiency in a CNC. differential mobility analyzer (DMA) A device that separates charged submicromete
34、r aero-sol based on the electrical mobility of a particle. DOP or DEHP The mineral oil dioctyl phthalate (DOP) or di (2-ethyhexyl) phthalate (DEHP); CAS# 117-81-7. With reference to filter testing, DOP also refers to a polydisperse aerosol of the described material. NOTE: Throughout this document, “
35、DOP” implies “either DOP or specified alternative liquid.” Current-ly, polyalphaolefin 4 Cst (PAO, CAS# 68649-12-7) has become widely used as a replacement for DOP. electromotive force (EMF) An electrical potential difference that produces or tends to produce an electrical current. The unit of measu
36、re is the volt. hysteresis A phenomenon that occurs in magnetic and ferromag-netic materials, as well as in the elastic, electric, and magnetic behavior of materials, in which a lag occurs between the application and the removal of a force or field and its subsequent effect. Electric hysteresis oc-c
37、urs when applying a varying electric field, and elastic hysteresis occurs in response to a varying force. lag block, temperature A solid block of metal used in a dry air temperature chamber, usually made of aluminum or copper and cylindrical in shape, intended to improve temperature stability of a t
38、emperature bath and equilibrium be-tween the UUT and the temperature standard. Holes are drilled in one end to the appropriate length for in-sertion of probes. laser aerosol spectrometer An aerosol particle sizing instrument that measures in the nanometer to micrometer size range and typically provi
39、des the particle size distribution on a displayed graph or table with usually 16 or more size channels. Mach number The speed of an object moving through air, or any other fluid substance, divided by the speed of sound as it is in that substance for its particular physical conditions, in-cluding tho
40、se of temperature and pressure. mass mean diameter of aerosol The average particle size of the mass distribution of the aerosol. Typically, since the mass of a particle varies as the cube of its diameter, most of the mass of an aerosol tends to be in the larger sizes, resulting in the mass mean bein
41、g larger than its count or number mean. mass median diameter (MMD) of aerosol The particle diameter size that is the 50th percentile of the mass distribution of the aerosol; i.e., 50% of the mass of the aerosol is made up of particles small-er than the mass median diameter, and 50% of the mass of th
42、e aerosol is made up of particles larger than the mass median diameter. national metrology institute (NMI) An organization providing national or international primary test standards used in the unbroken chain of traceability of test equipment. NOTE: Traceability to national metrology institute stand
43、ards does not al-ways require the use of the NMI of the country in which a calibration laboratory is located. optical particle counter (OPC) A light-scattering instrument with display or record-ing means to count and size discrete particles in air and other gases. Also referred to as a discrete part
44、icle counter (DPC). out-of-tolerance Exceeding the values of an error permitted by the specifications or regulations for a given measuring instrument. polyalphaolefin (PAO) The mineral oil PAO CAS# 68649-12-7. With refer-ence to filter testing, PAO also refers to a poly-disperse aerosol of the descr
45、ibed material. polydisperse DOP An aerosol having a mass median diameter (MMD) of approximately 0.45 m, a light-scattering geomet-ric diameter of approximately 0.72 m, and a light-scattering mean droplet-size distribution as shown in Echols and Young, NRL 5929. polymicrosphere generator A generator
46、utilizing atomizer or ultrasonic vibration principles to aerosolize polystyrene latex (PSL) mi-crospheres at a consistent and stable concentration. polystyrene latex (PSL) or polystyrene microspheres Test aerosol made using solid, monodisperse polysty-rene particles of a known size. NOTE: Polystyren
47、e microspheres do not contain natural rubber latex, which has been shown to poten-tially cause allergic reactions on contact with skin. pressure, absolute Absolute pressure is zero referenced against a perfect vacuum, so it is equal to gauge pressure plus atmos-pheric pressure. 8 IEST 2012 All right
48、s reserved Institute of Environmental Sciences and Technology IEST-RP-CC013.3 pressure, atmospheric The force per unit area exerted against a surface by the weight of a column of air above that surface at any given point in the Earths atmosphere. pressure, differential The difference in pressure bet
49、ween two points. pressure, gauge Zero referenced against ambient air pressure, so it is equal to absolute pressure minus atmospheric pressure. Negative signs are usually omitted. resistance temperature detector (RTD) A general term for a device that senses temperature by measuring resistance of a material. As tempera-ture changes, the resistance of the material changes in a known predictable fashion. Reynolds number (Re) In fluid mechanics, a dimensionless number that gives a measure of the ratio of inertial forces to vis-cous forces and consequently quantifies
