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Questions and answers on Environmental Engineering standards     

Questions on test objects and test severity for environmental conditions according to ETS 300 019 series

  1. In telecommunications networks, i.e. outside plant, telecommunications equipment as well as components are installed.

    What is the test object in the ETS 300 019-2 series, equipment or component?

    Is the application of the test programme and related test severity on components and equipment the same?

    Is the test severity applied on component more severe than on equipment?

  2. In many cases the different equipment and components are exposed to the same environmental conditions (climatic, mechanical etc.). Shall the same relevant environmental test programme be applied to the different equipment and/or components exposed to the same environmental conditions?


In the introduction documents for the ETS 300 019-1 and ETS 300 019-2 series it is explicit mentioned that the standards are related to equipment. Translations from macro climate as defined in the ETS to micro climate, as can be found inside the equipment, is considered to be the responsibility of the manufacturer when qualifying components.

Questions on ETS 300 019 1-1 to 1-4

After selecting the appropriate classes in ETS 300 019-1-1 to ETS 300 019-1-4, will testing have to be performed for every environmental parameter? By this I refer to the environmental parameters indicated in ETS 300 019-2-1 to ETS 300 019-2-4.  Each parameter has a characteristic severity, yet are tests only required for those parameters with a corresponding test severity, or must they be carried out for every parameter regardless if they have a test severity or not? I have read ETR 035 yet I am still unsure as to which tests must be performed for equipment certification.


The guidance that you require is found in the introductions to 300 019-1 and 300 019-2. The introduction to each part is contained in the -0 document  e.g. 300 019-1-0 and 300 019-2-0. A short answer is that if no test severity is provided, then a test is normally not appropriate - either because the condition is considered to be benign or that no suitable IEC 60068-2 test exists (the notes say which).

Question on ETS 300 019 (particularly 1-3 and 1-4) and TR 101 075

For non-weather protected locations 2 categories are given.  The 'extended' category is said to cover all ETSI countries. GSM and GSM based technologies are increasingly being accepted worldwide e.g. China, Australia, Morocco, the US, South America etc etc.  Is there any ETSI recommendation for environmental specifications for GSM technologies applied outside of ETSI countries (other than referring to the IEC documents)?

I have also noted that the classification for weather protected installations does not have different categories for the the different regions of Europe.  In the case of non-temperature controlled conditions were heat traps may occur, differences could potentially be significant. Does ETSI have any standards or recommendations regarding this?


ETSI only covers those conditions in Europe - a similar report (IEC 60721-4-4) which will shortly be issued, covers world-wide conditions - this can be found on the IEC TC 104 web page or is available from your national committee.  I n addition, ETSI has a new work item which will extend the scope to extreme telecomms environmental conditions - this will be a new class (T4.2) and is currently being formulated.

Question on ETS 300 019-1-4: Countries covered

In section 4.1, there are these descriptions: "Class 4.1 applies to many ETSI countries" and "Class 4.1 E covers all ETSI countries."

Q1: Which countries are included in ETSI countries? Does "all ETSI countries" include non-European countries? Could you list all the ETSI countries?

Q2: Which countries are the "many" ETSI countries? Can you list them?


The new issues of the documents will make this point clear. These are extracts from the new version of ETSI EN 300 019-1-4:

“Class 4.1 applies to most of Europe.  See note in Class 4.1E.”

“Class 4.1E covers all of Europe”.

This is the Note in 4.1E:

“NOTE: The climatic conditions in this class do not correspond to an IEC 60721-3-4 class. In order to define a non-weather protected class covering European locations where the mean value of the annual extreme values -45°C is chosen as the low temperature and +45°C as the high temperature for the class 4.1E.”

Question on ETS 300 019-1-4: Solar and ambient temperature for testing

Climatic conditions for environmental classes Class 4.1E show solar application of 1120w/m2 but does not advise at what ambient.

  1. Can solar tests be conducted in an ambient of 25Deg C?


For conformance you need the high temperature in combination with solar radiation.

2.  If they have to be conducted in an ambient of 45Deg C, can you advise which standards you are referencing?


There are no other references. The approach of simulation solar radiation by raising the temperature by 15 degC is based on the ETSI committee technical expertise.

Questions on ETS 300 019-2-2: Transportation

I am currently performing the Class 2.3 Public Transportation Random Vibration Test.
It seems very severe, the levels are 100x typical ASTM random profiles for transportation testing. I have two questions:

Are the random vibration levels for Class 2.3 Public Transportation testing correct? In the latest revision of ETS 300 019-2-2, V2.1.2 (1999-09), the levels are:        
5 to 20 Hz 1 m2/s^3 ASD       
  20 to 200 Hz - 3 dB/oct


The levels in the ETSI document have been checked and found to be correct. We do not know your referenced ASTM level but we suspect that you may have made an error in performing the dimension conversion.

The random vibration levels for Class 2.3 Public Transportation are the same as the other Classes 2.1 Very Careful Transportation and Class 2.2 Careful Transportation. Is this correct? Given the severity of the Public Transportation levels, should the the Careful and Very Careful levels be less.


Yes you are correct, the severity of the random vibration is the same for all transportation classes (the difference in classes are the shock levels).

Question on ETS 300 019-2-2: Water test

In the table 5 on page 12 of ETS300 019-2-2 V2.1.2 (1999-09), regarding the water test, "Rb:Impacting water, Method 2.2" in "IEC 60068-2-18" is referred. However there is not a Method Rb 2.2 in the IEC 60068-2-18 (2nd edition, 2000-10), there is only the Method Rb1.1, 1.2 and 2. So I cannot specify the test method. I wonder if "Rb 2.2" in the table 5 might be a miswording for "Rb 1.2"?


You are right. IEC 60068-2-18 has been recently modified (ed. 2; 2000-10). The test method reported in ETS 300 019-2-2 made reference to the previous edition (ed. 1; 1989-04+ A1:1993-03). In the second edition the impacting water tests (Rb) have been renamed due to the fact that the method Rb1 has been cancelled. In practice the 'old' Rb 2.2 test is now called Rb 1.2. Only the name has changed, the test method and the test severities are the same as before. 

The current version will be updated in the future to reflect the new IEC standards.

Question on ETS 300 019-2-2: Humidity test

In ETS 300 019-2-2:1994, Table 5 (Class 2.3), for the relative humidity test with the rapid temperature change, the listed test duration is 2 cycles. At the end of one cycle, IEC states that the temperature limit is between 22C and 28C, and that the humidity should be between 95% and 100% RH.  When going to the next cycle, it is required to ramp humidity back down to between 45% and 75% RH, or can the relative humidity be maintained at the high levels?


Yes, the relative humidities must be maintained at high levels.

I am wondering if a stabilization period is required between the two cycles.


No stabilization period is required between the two cycles.

Question on ETS 300 019-2-2

I am referring to ETS 300 019-2-2 printed May 1994: Environmental conditions and environmental tests for telecommunications equipment; Part 2-2: Specification of environmental tests Transportation; Table 5: Test specification T 2.3: Public Transportation - climatic tests air temperature high under test severity specifies 85C under condition (10) & (12).

Note 12 says that an additional test of 85C for 6 hr shall be conducted on unpackaged equipment only. Does this mean since we ship our products packaged we don't test to 85C but only to 70C? Or does this mean, to ensure product safety inside a box from solar radiation, all products should be tested unpackaged at 85C?


When the standard transportation is in a package and as such defined in the products specification, the lower temperature at 70 degC is applicable.  If the package is not protected against solar radiation then the product must be additionally tested in an unpacked condition for 6-hours in 85 degC test temperature.

Questions on ETS 300 019-2-3: Climatic tests 

For the alternative climatic test methods listed in ETSI 300 019-2-3 on all classes (class 3.1, 3.2, 3.3, 3.4, 3.5), what is the time period that the equipment should be tested for at each points S, A, B, C, ....


The notes associated with the climatograms require that specimen (equipment under test) stays at the corner points for a minimum duration of 1h after temperature stabilization is achieved.

In ETS 300 019-2-3:1994, Table 4 (Class 3.2), for the high and low air temperature tests, is it okay to have the systems powered on before reaching the 16 hour dwells at -5C and 45C/55C?



Do the climatic test durations take into account the time required for the unit under test to reach temperature stability?  If not, should I add additional hours before the test duration to ensure that stability is met?


Stability need to be obtained before the start the of the required duration.

Question on ETS 300 019-2-3: "Characteristic Severity" and "Test Severity"

I refer to document ETS 300 019-2-3 (Specification for environmental tests. Stationary use at weatherprotected locations), Page 10, Table 2.  Please could you clarify the categories "Characteristic Severity" and "Test Severity".  I'm not sure why some tests appear to have a characteristic severity quoted, but there is no need to test to this?


The guidance that you require is found in the introductions to 300 019-1 and 300 019-2.  The introduction to each part is contained in the -0 document  e.g. 300 019-1-0 and 300 019-2-0.

The characteristic severity is the conditions that can be expected to be found at the telecomms location described by the class using IEC 60721-3 conditions. This is fully described in the part 1 series of 300 019. The Part 2 documents then describe appropriate tests where necessary. If no test is given in the test severity column then the condition is either considered to be benign or there is no appropriate IEC 60068-2 test available (the notes say which).

Question on ETS 300 019-2-4: Vibration/shock test loads specified

The units for the load levels (acceleration) specified in table 3 are give in m/s2. Please confirm the correctness of the units since the specified loads seem to be very low (e.g. sine load 0.4 g only). Units in g, resulting in 9.81 times higher loads, would be expected instead.


The committee considers that the standard is correct and reflects the real environmental conditions experienced in this class.

Question on ETS 300 019-2-4: Temperature tests

We have to develop an equipment according to the 300 019-2-4 T4.1E standard. The temperature range asked by the product management is (-45°C ;+45°C) with 1120W/m². Our product is equipped with a solar-shield.
I have a question on the temperature tests :
- low temperatures : -45°C or -55°C?
- high temperatures : +45°C OR +45°C with solar load?


Please see notes 1 & 2 in the standard – If the equipment is protected from heat irradiation and solar gain (i.e. You have fitted a solar shield and have adequate ventilation) you need to test at -45°C and +45°C (not +60°C which we assume you mean).

Question on ETS 300 019-2-4: Damp heat cyclic tests

In table 2: Test Spec T 4.1E : Stationary use in non-weather protected locations, the damp heat cyclic test defines parameters of +30C, 90-100%RH in accordance with IEC 60068-2-30.

Does this 30C define the maximum temp for this test (which in the IEC graph for variant 1 is +40 or +55), or does it define the temperature from which the cycle should start?


Yes the 30 degC is maximum temperature as explained in the related note.

Question on ETS 300 119-3 and ETS 300 119-4: Weight measures

In point 5.1 and 5.2 of ETS 300 119-3 it is specified that the Weight must be expressed in SI unit force in N (more properly in kN). On the other hand, in point 6.1 of ETS 300 119-4 it is specified that the Weight shall be expressed in Kg. What is correct, N or Kg?


Both are correct:

In ETS 300119-3 point 5 the subject is "floor loading" and this must be given in kN/m2, as it refers to the force that the racks make towards the floor. 

In 6.1 of ETS 300 119-4 the subject is the weight of a subrack, in the meaning that the people carrying out the installation shall be able to handle it, and this must be given in Kg.

Question on ETS 300 753: Acoustic noise

In the standard is defined the declared A-weighted sound power specification and the high temperature A-weighted sound power one. We consider the case of telecommunication base stations in which the cooling fans generate environmental acoustic noise. 

Is it so that the acoustic noise should be specified only according to the LwAd and not yet according to HLwad at all?


ETSI chose not to set high limits because this gets into the realm of health and safety.  That is, while not very likely, some types of outdoor communications equipment can potentially be a source of hearing damage if someone is in close proximity to it for a long time (hours). So, at the time the document was developed, there was a worry that ETSI limits for high levels would come into conflict with national or regional health and safety limits.  Since, these values are not the same everywhere, this becomes a very messy issue.

When HLwad will be updated to be relevant, will the certain limits be defined as presented for LwAd?


EE1 thinks that the rationale noted above will not change and ETSI will remain focused only on  the lower level LwAd limits.

When the recommendations for outdoor solutions will be defined as requirements? What about some specifications for source directionality?


Since the original document was issued, there has been no work to address the outdoor questions.  The information on outdoor noise was put in as an attempt to provide a framework for outdoor problems. Setting limits for the outdoor noise is inherently much more difficult than for indoors.  It was hoped that interested parties would come back to ETSI with new information/data/suggestions, and that this would renew the discussion.  To the best of our knowledge, there has been very little feedback to date so no work has begun.

Question on ETS 300 753: Reading measurements

In relation to ETS 300 753 spec (Acoustic Noise Emitted by Telecommunications Equipment) the values in Table 1 page 11 give LwAd for 3.1 (Telecommunication equipment room unattended) as 7.5 bels. My understanding was that LwAd which is the declared A-weighted sound power level was measured in Watts.

I am trying to compare this to another spec (NEBS/Bellcore) which measures the equivalent reading as an SPL of 83dB. How to I convert LwAd (Power) to a Sound Pressure Level (SPL) reading.


It is not possible to convert by calculation. Measurements need to be undertaken.  See ECMA TR/27: “Method for prediction of installation noise levels” for further information.

Question on ETS 300 753: Night-time simulation

Our cooling devices are used in Base Transceiver Stations all over the world, and a lot of our customers are requesting us to meet the ETS 300 753 standard for Acoustic noise emitted by telecommunications equipment.

We have for years been specialising in combined cooling units where a "passive" cooling device such as heat exchangers can remove the heat load up to a certain temperature whereafter the active cooling (air-conditioner) together with the passive is in function up to the specified maximum temperature.

Our question is relating to point A.3.2 in Annex A regarding Night-time simulation. If there's no need for active cooling at the temperature limit specified in the standard, will it then be necessary to force the air-conditioner to be functional?


Yes, the cooling system needs to be active and all noise emitting devices also need to be active.