1、Specifications and Tests forPiezoelectric Pressure and Sound Pressure TransducersReaffirmed 29 September 1995ISA37.101982 (R1995)Formerly ISAS37.101982 (R1995)STANDARDISA The Instrumentation,Systems, andAutomation Society TMCopyright 1982 by ISA. All rights reserved. Printed in the United States of
2、America. No part ofthis publication may be reproduced, stored in a retrieval system, or transmitted in any form or byany means (electronic, mechanical, photocopying, recording, or otherwise), without the priorwritten permission of the publisher.ISA67 Alexander DriveP.O. Box 12277Research Triangle Pa
3、rk, North Carolina 27709ISA-37.10-1982 (R1995), Specifications and Tests for Piezoelectric Pressure and Sound-Pressure TransducersISBN 0-87664-382-9ISA-S37.10-1982 (R1995) 3PrefaceThis preface, as well as all footnotes and annexes, is included for informational purposes and is not part of ISA-37.10-
4、1982 (R1995).This standard has been prepared as a part of the service of ISA, the international society for measurement and control, 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 t
5、his end, the Society welcomes all comments and criticisms 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.The ISA Stand
6、ards and Practices Department is aware of the growing need for attention to the metric system of units in general, and the International System of Units (SI) in particular, in the preparation of instrumentation standards, recommended practices, and technical reports. The Department is further aware
7、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 countries. Towards this end, this Department will endeavor to introduce SI and acceptable metric units in all new and revised st
8、andards to the greatest extent possible. The Metric Practice Guide, which has been published by the Institute of Electrical and Electronics Engineers as ANSI/IEEE Std. 268-1992, and future revisions, will be the reference guide for definitions, symbols, abbreviations,and conversion factors.It is the
9、 policy of ISA to encourage and welcome the participation of all concerned individuals and interests in the development of ISA standards, recommended practices, and technical reports. Participation in the ISA standards-making process by an individual in no way constitutes endorsement by the employer
10、 of that individual, of ISA, or of any of the standards which ISA develops.This Standard was originally prepared by the SP37.10 Committee which operated under the guidance of SP37.The following individuals served on the original SP37.10 Subcommittee:NAME COMPANYN. Keast, Chairman Bolt, Beranek and N
11、ewman, IncorporatedG. T. Cozad McDonnell Douglas CorporationL. Horn National Bureau of StandardsR. W. Lally PCB PiezotronicsJ. Rhodes Endevco Corporation4 ISA-S37.10-1982 (R1995)The following individuals served on ISA Committee SP37, who reaffirmed ISA-S37.10 in 1995:NAME COMPANYE. Icayan, Chairman
12、Westinghouse Hanford Co.J. Weiss Electric Power Research Inst.P. Bliss, Deceased ConsultantM. Brigham The Supply SystemD. Hayes LA Dept. Water i.e., Temperature: 25 10C (77 18F); Relative Humidity: not to exceed 90 percent; Barometric Pressure: 730 70 millimeters Hg (29 3 in. Hg).Terminology used he
13、re is defined either in ISA-S37.1 or in 4.3 of this document. An asterisk appears beside the paragraph number of those terms defined in S37.1.It is important that all transducer performance characteristics be listed independent of the characteristics of any amplifier and/or non-integral cables suppl
14、ied with the transducer. (Performance characteristics may also be supplied including the effects of amplifiers and cables, if so identified as supplemental information.) In those cases where such characteristics cannot be stated independent of amplifier properties, the pertinent amplifier and cable
15、type, part number, and properties shall also be specified.All performance characteristics are applicable under the conditions specified for Load Impedance. Note that this practice is used in lieu of specifying “open-circuit“ output characteristics (an earlier practice, which did not permit verificat
16、ion of such characteristics since all ancillary equipment has a finite value of input impedance).NOTE In the following, separate statements are given for pressure transducers and for piezoelectric sound-pressure transducers in those cases where current terminologies differ for the two applications.4
17、.2.1 Required performance characteristics4.2.1.1 Range*a) Pressure transducers. The range, usually expressed as “ _Pa (psi)“ or “0 to _Pa (psi.)“b) Piezoelectric Sound-Pressure Transducers. The range is usually expressed as “_dB sound pressure level (SPL) to _dB SPL re 20 Pa.“*Defined in ISA-S37.114
18、 ISA-S37.10-1982 (R1995)4.2.1.2 Sensitivity, charge or voltage*a) Pressure Transducers. The voltage sensitivity is expressed as “_mV per Pa (psi) _%,“ or as “_ _mV per Pa (psi).“ Equivalently, charge sensitivity may be expressed as “_ picocoulombs per Pa (psi) _%,“ or as “_ _ picocoulombs per Pa (ps
19、i).“In any case, it is assumed that the pressure and electrical parameters are both reported as peak, average, or rms values unless stated otherwise.b) Piezoelectric sound-pressure transducers. The voltage sensitivity level is expressed in dB as 20 times the logarithm to the base 10 of the ratio of
20、the sensitivity to the reference sensitivity. That is, sensitivity level S, re 1V/Pa, is S = LV Lp= 20 log10V/pwhere Lvis the output voltage, re 1V, produced by applied sound pressure level Lp,re 20Pa. Appropriate tolerances should be shown for a specified nominal value.Alternatively, the charge sen
21、sitivity level may be expressed as “_ _dBre 1 picocoulomb per Pascal.“4.2.1.3 Frequency response*a) Pressure transducers. This is expressed as “within _% of the sensitivity at _ Hz from _ to _ Hz.“ The method for determining this frequency response should be described.b) Piezoelectric sound-pressure
22、 transducers. Frequency response shall be specified as “_ type frequency response) within 3 dB (or, alternatively, within 1 dB) from _ Hz to _ Hz.“ The quantity entered into the first blank shall be one of the following (as defined in 4.3): calculated frequency response*, pressure response, free-fie
23、ld grazing incidence response, free-field normal incidence response, or free-field random incidence response.Frequency response shall be referred to a frequency within the specified frequencyrange of the transducer and to a specific fluid. The methods of mounting the trans-ducer and applying the tes
24、t fluid should both be specified.4.2.1.4 Linearity*a) Pressure transducers. Linearity is normally expressed as “_ linearity within _% of full (or a specified partial) scale output.“ The type of linearity to be entered in the first blank above shall be one of the straight line types defined in ISA-S3
25、7.1; namely: end point, independent, least squares, terminal, or theoretical slope.b) Piezoelectric sound-pressure transducers. Linearity is generally expressed as “_ linearity within _dB.“ The type of linearity specified in the first blank shall be one of the straight one types defined in ISA-S37.1
26、.4.2.1.5 Proof pressure*a) Pressure transducers. Proof Pressure shall be expressed as (application of) “_Pa (psi) for _ minutes“ (will not cause changes in transducer performance that exceed its specified error limits).*Defined in ISA-S37.1ISA-S37.10-1982 (R1995) 154.2.1.6 Burst pressure rating*a) P
27、ressure transducers. Burst Pressure Rating is stated as “_Pa (psi) applied _times for a period of _ minutes each“ (will not result in mechanical failure of the transducer housing).4.2.1.7 Thermal sensitivity shift*a) Pressure transducers. Thermal Sensitivity Shift is expressed in terms of a maximum
28、change from the (actual) room-temperature sensitivity level over the specified operating temperature range* as “_ % maximum, from _C(F) to _C(F).“b) Piezoelectric sound-pressure transducers. Thermal Sensitivity Shift is expressed as “ _dB“ (sensitivity level change over the specified operating tempe
29、rature range*) “from _C(F) to _C(F).“4.2.1.8 Temperature gradient error*Expressed as “less than _ mV output when subjected to a step-function temperature change from _C(F) to _C(F), applied to (specify particular part) of the transducer“ (at constant ambient pressure).State whether Procedure I or II
30、 of 6.7 is to be used to verify this characteristic.NOTE Alternatively, the temperature-gradient error may be expressed as equivalent Pa (psi) input (for pressure transducers), or in picocoulombs output for transducers to be used with charge amplifiers, or in dB SPL.4.2.1.9 Maximum and minimum ambie
31、nt temperature*Expressed as (the transducer can be operated indefinitely at any temperature within the range from) “_C(F) to _C(F)“ (without incurring a permanent calibration shift).4.2.1.10 Vibration error*a) Pressure transducers. Vibration error limits are expressed as “less than _ mV“ (or alterna
32、tely, picocoulombs) “rms output due to _ g rms acceleration along any axis over a frequency range from _ Hz to _ Hz.“ The errors shall be listed for each of three mutually perpendicular axes, or for that axis expected to have the largest vibration error. State whether a swept sinusoidal or broad-ban
33、d random vibration input is to be employed. In the latter case it is preferable to show a graphical representation of the vibration program.b) Piezoelectric sound-pressure transducers. Vibration error limits may be expressed as “less than _ dB equivalent SPL output due to _ g rms acceleration along
34、any axis over a frequency range from _ Hz to Hz.“ State whether a swept sinusoidal or broad-band random vibration input is to be employed.NOTE Alternatively, the equivalent SPL output may be expressed relative to peak acceleration, provided that this is made clear and that the type of vibration wave
35、form is specified.*Defined in ISA-S37.116 ISA-S37.10-1982 (R1995)4.2.1.11 Other environmental conditions*Other pertinent operating* or non-operating* environmental conditions that shall not affect the transducer performance beyond the specified limits shall be listed; examples are as follows:a) Mech
36、anical Shockb) Humidityc) Salt Sprayd) Nuclear Radiatione) Electromagnetic Interferencef) Acceleration (steady)g) Ambient PressureThe test conditions for determining such properties shall be identified.4.2.1.12 Sensitivity stabilitya) Pressure transducers. Sensitivity stability shall be stated as, “
37、The sensitivity shall not vary more than _ % of its room-temperature value when subjected to _ temperature cycles between _C(F) and _ C(F) and to _ pressure cycles up to _ Pa (psi).“b) Piezoelectric sound-pressure transducers. Sensitivity Stability shall be stated as, “The sensitivity level shall no
38、t vary more than _dB when subjected to _ temperature cycles between _C(F) and_C(F) and to sound pressure levels up to _dB re 20Pa at _ Hz.“4.2.1.13 Ambient-pressure sensitivity shift*a) Piezoelectric sound-pressure transducers. The allowable sensitivity shift due to variations in ambient pressure sh
39、all be expressed as, “The microphone sensitivity level will not vary more than _ dB when operated at any ambient pressure within the range from _ Pa (psia) to _ Pa (psia).“4.2.1.14 Resonant frequency amplification factora) Pressure transducers. Resonant frequency amplification factor at the lowest r
40、esonant frequency shall be expressed as “the amplification factor at resonant frequency _ Hz shall not exceed _.“b) Piezoelectric sound-pressure transducers. Resonant frequency amplification factor at the lowest resonant frequency shall be expressed as “the amplification factor resonant frequency _
41、Hz shall not exceed _ dB.“4.2.1.15 Directivity*a) Piezoelectric sound-pressure transducers. The Directivity shall be specified as an allowable envelope for a specified directivity characteristic (directional response pattern, see 4.3).*Defined in ISA-S37.1ISA-S37.10-1982 (R1995) 174.2.2 Optional per
42、formance characteristics4.2.2.1 Resonant frequency characteristics of sensing elementsAmplification (damping) at additional frequencies shall be expressed as in 4.2.1.14.4.3 Additional terminology4.3.1 decibel (dB): (see ANSI-S1.1 reference) (see also Sound Pressure Level). A unit of level, whereP1=
43、 a power, or, quantity directly proportional to power. Pref= a reference power, or, a corresponding reference quantity proportional to power.4.3.2 diffuse-field response: A frequency response of a piezoelectric sound-pressure transducer with the sound incident from random directions.4.3.3 directivit
44、y characteristic: (Directional Response Pattern) (see Beranek reference). A plot of the sensitivity level of piezoelectric sound-pressure transducer vs. the angle of sound incidence on its sensing element relative to the sensitivity level in a specified direction, and at a specified frequency.4.3.4
45、equivalent volume: (see ANSI-S1.12 reference). The volume of a gas enclosed in a rigid cavity which would give the same acoustical input impedance as that of the piezoelectrical sound-pressure transducer.4.3.5 free-field frequency response: (see ANSI-B88.1 reference). The free-field frequency re-spo
46、nse of a piezoelectric sound pressure transducer is the ratio, as a function of frequency, of the transducers output in a sound field to the free-field sound pressure existing at the transducer location in the absence of the transducer.4.3.6 free field (sound): (see ANSI-S1.1 reference). A free soun
47、d field is one existing in a homo-geneous, isotropic medium free of any acoustically-reflecting boundaries.4.3.7 free-field grazing incidence response: A free-field frequency response of a piezoelectric sound-pressure transducer with the sound incident parallel to a specified sensing surface of the
48、microphone.4.3.8 level: (see ANSI-S1.1 reference). A measure of the logarithm of the ratio of some quantity to a reference quantity of the same kind. The reference quantity must be identified.4.3.9 pressure (frequency) response: The pressure frequency response (pressure response) of a piezoelectric sound-pressure transducer is the ratio, as a function of frequency, of the trans-ducer output to a sound pressure input which is equal in phase and amplitude over the entire sensing surface of the transducer.The pressure frequency response is generally equal to the free-field frequency response at
