1、 NEMA SB 10 AUDIO STANDARD FOR NURSE CALL SYSTEMS NEMA SB 10-1991 (R1998, R2005, R2010) Audio Standard for Nurse Call Systems Reaffirmed November 18, 2010 Published by: National Electrical Manufacturers Association 1300 North 17th Street, Suite 1752 Rosslyn, VA 22209 www.nema.org Copyright 1991 by N
2、ational Electrical Manufacturers Association. All rights, including translation into other languages, reserved under the Universal Copyright Convention, the Berne Convention for the Protection of Literary and Artistic Works, and the International and Pan American Copyright Conventions. NOTICE AND DI
3、SCLAIMER The information in this publication was considered technically sound by the consensus of persons engaged in the development and approval of the document at the time it was developed. Consensus does not necessarily mean that there is unanimous agreement among every person participating in th
4、e development of this document. NEMA standards and guideline publications, of which the document contained herein is one, are developed through a voluntary consensus standards development process. This process brings together volunteers and/or seeks out the views of persons who have an interest in t
5、he topic covered by this publication. While NEMA administers the process and establishes rules to promote fairness in the development of consensus, it does not write the document and it does not independently test, evaluate, or verify the accuracy or completeness of any information or the soundness
6、of any judgments contained in its standards and guideline publications. NEMA disclaims liability for any personal injury, property, or other damages of any nature whatsoever, whether special, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, app
7、lication, or reliance on this document. NEMA disclaims and makes no guaranty or warranty, express or implied, as to the accuracy or completeness of any information published herein, and disclaims and makes no warranty that the information in this document will fulfill any of your particular purposes
8、 or needs. NEMA does not undertake to guarantee the performance of any individual manufacturer or sellers products or services by virtue of this standard or guide. In publishing and making this document available, NEMA is not undertaking to render professional or other services for or on behalf of a
9、ny person or entity, nor is NEMA undertaking to perform any duty owed by any person or entity to someone else. Anyone using this document should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exercise of reasonable care
10、in any given circumstances. Information and other standards on the topic covered by this publication may be available from other sources, which the user may wish to consult for additional views or information not covered by this publication. NEMA has no power, nor does it undertake to police or enfo
11、rce compliance with the contents of this document. NEMA does not certify, test, or inspect products, designs, or installations for safety or health purposes. Any certification or other statement of compliance with any health or safetyrelated information in this document shall not be attributable to
12、NEMA and is solely the responsibility of the certifier or maker of the statement. - STD-NEMA SB LO-ENGL 1991 6470247 0527378 653 iiai Table of Contents FOREWORD SCOPE PURPOSE .i INTRODUCTiON HISTORY . ii intercom 1 Microphone 1 ModeA . 1 ModeB . 1 Nurse Control Station (NCS) . 1 Patient Station . 1
13、Pillow Speaker . 1 Signal to Noise Ratio (S/N) 1 Sound Pressure Level (SPL) 1 Section 1 DEFINITIONS PinkNoise . 1 Speaker . 1 Equipment Set-up . 3 System Output Levels . 3 System input Levels 3 AmbientSPL 3 Minimum Signal to Noise Ratio 3 Figure 2-1, Setup For Mode A Level (NCS) 4 Figure 2.2, Setup
14、For Mode B Level . 5 Figure 2.3. Setup For Mode B S/N Ratio . 6 Figure 2-4. Setup For Mode A S/N Ratio (NCS) . 7 Test Equipment Required . 9 Figure 3.1, Test Setup . 9 Figure 3.2, Test Setup . 10 Section 4 TEST PROCEDURE Data Recording . 11 NCS OutputPatient Station Input Sensitivity . 11 Mode A Sig
15、nal to Noise (Patient Station) . 11 Mode A Level Pillow Speaker) 11 NCS SN From Pillow Station . 11 Mode B Level (Patient Station) 13 Mode B S/N (Patient Station) . 13 Mode B Level (pillow Speaker) 13 Mode B SN (pillow Speaker) . 13 Table 4-117. Nurse Call Audio Performance Data Worksheet 12 Section
16、 2 GENERAL REQUIREMENTS Section 3 TEST EQUIPMENT REQUIRED Foreword The preparation of this Standard Publication was initiated in response to input from the Velerans Administration. Input from other interested parties has also been sought and evaluated. Inquiries, comments, and proposed or recommende
17、d revisions should be submitted u) the concerned NEMA product subdivision by conracting the: Vice President, Engineering National Electrical Manufacturers Association 2101 L Street, N.W., Suite 300 Washington, DC 20037 Scope This publication contains requirements and test pmedures for the evaluation
18、 of the audio quality of installed nurse cail systems utilizing loud speaking nurse control stations in conjunction with loud speaking patient stations and pillow speakers. Purpose This document provides a standardized method for testing the audio of an installed nurse call system to assure that the
19、 installation methods used provide an adequate level of audio quality. Introduction A nurse cail system is the common name for the equipment used in health care facilities to allow communication, aurally/ visually, or both, between staff and patients. Currently, there is no standard definition of ei
20、ther what a nurse call system must be capable of doing or the minimum equipment required to perform nurse call functions. Local codes usually specify minimum equipment and features for installations within specific regions governed by the code, but there is no uniform standard that supersedes the lo
21、cal codes and ordinances. Features and functions of a nurse cai1 system can, therefore, vary widely from installation to instaliation. General conclusions can be drawn from observations of many installations. One is that a minimum nurse. call system consists of three basic components: 1. Call cord p
22、endant or pillow speakers which are located at the patients beds that allow the patients to place calls for assistance: 2. An indicator lamp, located usually in the comdor outside of the patients rooms, that illuminates to visually indicate that the patient has placed a call for assistance; and 3. A
23、n annunciator panel, located at the nurses staff office, ward clerks desk, and such, which contains a display capable of indicating which patients rooms have registered requests for assistance. Many nurse call systems have additional capabilities, including two-way aural contact between the annuncia
24、tor panel (or master station) and the patients moms to answer patients questions; requests for food, wafer, and such; and other non-emergency information. 1 History This NEMA Standards Publication is the result of many years of research and investigation by members of NEMA. It was developed through
25、consultation among manufacturers, users, and testing laboratories. It reflects study of the following standards and technical documents that were helpful in the preparation. American National Standards Institute 11 W 42nd Sn-eet New York, NY 10016 ANSVNFPA 70-1990 National Electrical Code ANSvNFpA99
26、-1990 Standard for Health Care Facilities ANSI/IEEE 602-1986 IEEE Recommended Practice for Electrical Systems in Health Care Facilities ANSI/UL 1069-1989 Hospital Signaling And Nurse Call Equipment Canadian Standards Association, inc. 178 Rexdaie Boulevard Rexdaie, Ontario, Canada M9W 1R3 CSA C22.2
27、NO. 125-1984 Class 8711 -01 Elecuomedical Equipmetal Federal Communications Commisfion 2025 M Street, N.W. Washington, DC 20554 FCC Rules has the capabil- ity of annunciating calls from patientsrooms by aural/vis- ual, or both, means and has the capability of providing verbal communication between t
28、he patient and the nursdward clerldduty clerkland such, sometimes called “master” or “master station” or “NCS.” NEMA Standard 5-9-1991. 1.6 Patient Station is a device located in a patients room containing the circuitry required to provide both microphone and loudspeaker functions as required by the
29、 nurse call intercom. The patient station is the location of one of the parties in a two-party intercom communication. NEM4 Standard 5-9-1991. 1.7 Pillow Speaker is a device, sometimes called a pendant conuol, located at a patients bed and that contains the ckuitry required to provide both microphon
30、e and loudspeaker functions, as required by the nurse Cali inter- com. The pillow speaker is often an extension of the patient station and may be capable of controlling other devices external to the nurse call system, such as a televi- sion set. NEMA Standard 5-9-1991. 1.8 Pink Noise is a random noi
31、se thal is band-limited at 12 dB per octave, 20 Hz to 20 Khz equal energy per octave. NEMA Standard 5-9-1991. 1.9 Signal to Noise Ratio (SM) is the calculated ratio of the measured rms electrical value taken at the speaker when generating the minimum rated acoustic output level divided by the measur
32、ed rms electrical value at the speaker when the microphone has been replaced with an equivalent resistive load. NEW Standard 5-9-1991. 1.10 Sound Pressure Level (SPL) is a quantitative measurement of loudness on a logarithmic scale refer- enced to 20 Pa (20 micro pascal). NEMA Standard 5-9-1991. 1.1
33、1 Speaker is an electro-acoustic transducer that NEMA Standard 5-9-1991. converts electrical energy to acoustic energy. STDeNEMA SB 10-ENGL L99L b470247 0527182 084 111 SB 10-1991 Page 3 SECTION 2 GENERAL REQUIREMENTS 21 EQUIPMENT SET-UP 2.4.1 nie NCS input level (mode B) shall be 66 di3 SPL maximum
34、, neasd at the mirophone of the Ncs (see shall be: Figure 2-2). The equipment associated with the system under test 2.4.2 The patient station output level (mode A) shall be 76 Db SPL minimum measured on axis at a distance of 1 meter from the patient station speaker (see Figure 2-2). a. Comectiy inst
35、ailed per the manufacturers instructions and methods; b. Functioning properly per manufacturers swifications; c. and d. Configured to achieve a two-party intercom communication between the NCS and one patient station or pillow speaker. 2.4.3 The pillow speaker output level (mode A) shall be 76 dB SP
36、L minimum measured on axis at a distance of 1 meter from the pillow speaker (see Figure 2-2). 2.4.4 The patient station input level (mode B) shall be 66 dB SPL maximum measured at the microphone of the patient speaker (see Figure 2-1). 2.4.5 The pillow speaker input level (mode B) shall be 66 dB SPL
37、 maximum measured at the microphone of the pillow speaker (see Figure 2-1). 2.4.6 The NCS output levels (mode A) shall be 76 dB minimum measured on axis at a distance of 1 meter from NEM Standard 5-9-1991. NEM sw1dard5-9-1991. 22 SYSTEM OUTPUT LEVELS The output level shall be measured 1 meter on axi
38、s from the speaker of the receiving element of a tweparty inter- com communication and be referred to the input level at the msmiuing microphone as specified herein. NEMA Standard 5-9-1991. 23 SYSTEM INPUT LEVELS the NCS speaker (see Figure 2-1). The input level shall be measured at the microphone a
39、t the transmitting end of the two-party intercom communi- cation and shall be the minimum input supplied for the output level test. 25 MINIMUM SIGNAL To NOISE RATIO The following shall be the minimum S/N measured at 24 AMBIENTSPL 2.5.1 Patient Station Speaker: 35 dB (see Figure 2-3). The maximum amb
40、ient SPL at input and output trans- 2.5.2 pillow Speaker: 35 dB (see Figure 2-3). ducers shall not exceed 50 dB for valid test results. 2.5.3 NCS: 35 dB (see Figure 24). NEMA Standard 5-9-1991 STD*NEMA SB 10-ENGL 3973 II b470247 0527383 TL0 Speaker SB 10-1 991 Page 4 . System Circuitry - ? Sound lev
41、el Meter 14- I I I I I I I Pillow Speaker I I I 1 Meter ?- Amplifier Speaker Pink-Noise Generator Patient Station 66 dB SPL I 1 Meter I- 76 dJ3 SPL I 41- U/ Sound levei Meter 1 - Meter Flgure 2-1 Setup For Mode A Level (NCS) It shall be permissible to use either a patient station or a pillow speaker
42、 as the reference for the nurse station receiver level. The 1-meter distance must be maintained throughout the test, and all measurements taken on axis and all sources aligned on axis. NEMA Standad5-9-1991. STD*NEMA SB LO-ENGL L991 b470247 0527364 957 = SB 10-1 991 Page 5 Sound level Meter I 66 dB S
43、PL Pink-Noise 1 meter Generator * 7 Microphone Speaker Nurse Control Station (NCS) Pink-Noise Generator I - I I * 76 dB SPL I (-)=i I Sound Lcvcl Meter I meter .-e System Circuitry Patient Station , L 1 meter I I *- Pillow Spcaker Figure 2-2 Setup Mode B Level Patient Station/Pillow Speaker It shall
44、 be permissible to use either a patient station or a pillow speaker as a reference for the NCS input level. The 1-meter NEMA Standard 5-9-1991. distance must be maintained throughout the test and all measurements taken on axis and ail sources aligned on axis. SB 10-1991 Page 6 * I I System Circuitry
45、 I I Patient Open Microphone Leads Pink-Noise I Microphone Equivilant Impedance Nurse Control Station (NCS) I I 1 meter I I rms Volt Meter I I I I I 1 meter * - - - - - - - - - - - 76 dB SPL Pillow Speaker -3l)+ I L7“ L * Speaker Lines I I I u I I I I 1 I I I I I I I I Amplifier I W I,-J Nurse Contr
46、ol Station (NCS) 76 dB SPL Sound Icvcl Meter 1 meter mis Volt Meter System circuitry Input Figure 2-4 Setup For Mode A SIN Ratio (NCS) It shall be permissible to use either a patient station or pillow speaker as a reference for S/N ratio. See Figure 3-1. NEMA Standard 5-9-1991. SB 10-1991 Page 9 -I
47、I Open I I I I I I I I I I SECTION 3 TEST EQUIPMENT REQUIRED 3.1 The following test equipment shall be used to test the parameters of installed nurse call systems covered by this Standards Publication: 1. A pink-noise generator, with transformercoupled output, capable of providing signal levels of a
48、t least 1 v nns at 10 mA or signal levels sufficient to drive the nurse cai1 system, in all modes of intercom operation, to maxi- mum output levels, per manufactured specifications. 2. Arms reading voltmeter with a range of 10 v to 100 v; a minimum input impedanceof 100 k ohms; and a minimum equency
49、 responsr of 3 dB hm 100 Hz to 10 KHz. 3. A sound level meter with a range of 20 dB SPL to 120 dB SPL and frequency response conforming to ANSI “C weighting response characteristics. 4. An audio amplifier and speaker with frequency re- sponse of 3 dB over the range of 100 Hz to 10 KHz and capability of producing an SPL of 90 di3 at a distance of 1 meter measured on axis. 5. Patient station/pillow speaker test set (see Figure 3-1) as specified by the manufacturer. 6. NCS test set (see Figure 3-2) as spec
