1、CCITT RECMN*Om3 92 4862573 0579383 963 m INTERNATIONAL TELECOMMUNICATION UNION CCITT THE INTERNATIONAL TELEGRAPH AND TELEPHONE CONSULTATIVE COMMITTEE 0.3 (1 0/92) SPECIFICATIONS OF MEASURING EQUIPMENT CLIMATIC CONDITIONS AND RELEVANT TESTS FOR MEASURING EQUIPMENT Recommendation 0.3 CCITT RECMN*O-3 9
2、2 4862593 0579384 8TT FOREWORD The CCITT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCITT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a
3、view to standardizing telecommunications on a worldwide basis. The Plenary Assembly of CCITT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT between Plenary Assemblies is
4、 covered by the procedure laid down in CCIT Resolution No. 2 (Melbourne, 1988). Recommendation 0.3 was revised by Study Group IV and was approved under the Resolution No. 2 procedure on the 5th of October 1992. CCIT NOTE In this Recommendation, the expression “Administration” is used for conciseness
5、 to indicate both telecommunication administration and a recognized private operating agency. O ITU 1993 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in w
6、riting from the ITU. CCITT RECMN*O-3 92 W 9862593 0579385 73b Recommendation 0.3 CLIMATIC CONDITIONS AND RELEVANT TESTS FOR MEASURTNG EQUIPMENT (Melbourne 1988: revised 1992) Abstract Defines climatic conditions for operating, storage and transportation of measuring equipment specified in O-Series R
7、ecommendations, and identifies relevant test conditions. Keywords - climatogram; - environment; - humidity; - measurement; - temperature; - tester; - test equipment. 1 General The O-Series Recommendations specify measuring equipment for a wide range of applications. Reliable test equipment is an imp
8、ortant prerequisite when maintaining telecommunication equipment and telecommunication networks. The reliability of measuring equipment can be affected by the environmental conditions to which the equipment is exposed during its use. This Recommendation gives a range of climatic conditions for the o
9、peration of measuring equipment specified in the O-Series Recommendations. In addition, climatic conditions for transportation and storage of measuring equipment are defined. In order to be able to prove that the requirements of this Recommendation are fulfilled, test conditions simulating the vario
10、us environmental parameters are specified. Where possible, this Recommendation is based on standards produced by other bodies such as the International Electrotechnical Commission (EC) 11 or the European Telecommunications Standards Institute (ETSI) 2. 2 Climatic conditions for the operation of meas
11、uring equipment 2.1 Indoor operation Considering that measuring equipment will be used in most of the cases in weather-protected locations, the normal operating conditions specified in Figure U0.3 define the range of climatic conditions under which the equipment specifications shall be met. These co
12、nditions may be found in normal working areas, offices, telecommunication centres or storage rooms for sensitive products, etc. The normal operating conditions are maintained by heating, cooling and, where necessary, by forced ventilation. Humidity may normally not be controlled. Figure U0.3 implies
13、 that the measuring equipment is usually operated at a temperature of approximately 25 “C at a relative humidity of 45%. The dotted field in the centre of the climatogram of Figure 110.3 specifies the climatic conditions which will be experienced during 90% of the time. Recommendation 0.3 (10192) 1
14、CCITT RECMNlk0.3 92 W 48b257L 057718b b72 The exceptional operating conditions shown in Figure V0.3 may exist, e.g. following failure of the climate controlling system. Under these conditions, the measuring equipment shall still operate without irreversible faults. However, the measurement may be le
15、ss accurate. In some instances the measuring equipment may be exposed to solar radiation and to heat radiation from other sources (e.g. from room heating). Direct solar radiation should be avoided and the temperature in the vicinity of the equipment shall not exceed the limits of Figure U0.3. The eq
16、uipment may also be exposed to movements of the surrounding air due to draughts in buildings (e.g. through open windows). It shall not be subjected to condensation or precipitation. 45 40 35 30 o O -5 -1 o -20 1.5 1 .o _. O 5 10 20 30 40 50 60 70 80 85 90 100 Relative humidity (%) T0404240-93/601 Li
17、mits of normal operating conditions - - - - - - - - - Limits of exceptional operating conditions Field of 90% frequency of occurrence FIGURE 1/0.3 Temperature-humidity-chart for the operation of measuring equipment (weather-protected locations) 2.2 Operation of measuring equipment in other environme
18、nts Under study. 3 Transportation and storage During transport and storage, the measuring equipment shall tolerate, without irreversible failure, temperaturehumidity combinations as given by the following equations as shown in Figure 2/0.3. The limiting conditions are: 70 “C 2 Air temperature 2 -40
19、“C; 5% I Relative humidity I 95%; O. 1 g - m-3 I Absolute humidity I 29 g - m-3. 2 Recommendation 0.3 (10/92) The (uninterrupted) exposure time is limited to two months. Note - It is assumed that the measuring equipment is packed in its usual shipping container and that the ambient conditions mentio
20、ned above are those outside the package. 400 300 200 1 O0 50 2 1 0.05 0.001 O 10 20 30 40 50 60 70 80 90 100 Relative humidity in % T0404250-93/d02 FIGURE 2/0.3 Temperature-humidity-chart for transport and storage of measuring equipment (weather-protected locations) CCITT RECMN*0-3 72 M YB62571 0577
21、188 -IV5 4 Test conditions 4.1 Test conditions for indoor climates It is assumed that the measuring equipment meets the requirements of 8 2.1 if it tolerates the basic environmental testing procedures in accordance with IEC Publication 68-2-3 3. During these testing procedures, the measuring equipme
22、nt shall be placed in the testing chamber for four days. After a recovery time of two hours, the test specimen shall properly function and the specified error limits shall not be exceeded. Note - This requirement is provisional and requires further study. 4.2 Test conditions for other environments U
23、nder study. References IEC Publication 721-3-3 Classification of groups ana environmental parameters and their severities - Stationary use at weather-protected locations. Final Draft RETS 300 019-1-3 Equipment engineering (EE); Environmental conditions and environmental tests for telecommunications equipment - Part 1-3: Classification of environmental conditions - Stationary use at weather-protected locations. IEC Publication 68-2-3 Basic Environmental Testing Procedures. Part 2: Test Ca: Damp heat, steady state. 4 Recommendation 0.3 (10/92) Printed in Switzerland Geneva, 1993
