1 - AS 60068.2.68-2003 ENVIRONMENTAL TESTING - TESTS-TEST L: DUST AND SAND
4 - PREFACE
5 - CONTENTS
6 - INTRODUCTION
7 - 1 General
7 - 1.1 Scope
7 - 1.2 Description of test L
8 - 2 Normative references
8 - 3 Definitions
8 - 3.1 dust:
8 - 3.2 dust concentration:
8 - 3.3 humidity:
8 - 3.4 hygroscopic:
8 - 3.5 particle size:
9 - 3.6 sand:
9 - 3.7 sieve (square-meshed):
9 - 4 Test La: non-abrasive fine dust
9 - 4.1 Method La1: cyclic air pressure
9 - 4.1.1 Object
9 - 4.1.2 General description
9 - 4.1.3 Description of test apparatus
9 - 4.1.4 Test conditions
11 - 4.1.5 Preconditioning
11 - 4.1.6 Initial measurements
11 - 4.1.7 Testing
11 - 4.1.8 Intermediate measurements
11 - 4.1.9 Recovery
11 - 4.1.10 Cleaning
11 - 4.1.11 Final measurements
11 - 4.1.12 Information to be given in the relevant specification
12 - 4.2 Method La2: constant air pressure
12 - 4.2.1 Object
12 - 4.2.2 General description
12 - 4.2.3 Description of test apparatus
13 - 4.2.4 Test conditions
14 - 4.2.5 Preconditioning
14 - 4.2.6 Initial measurements
14 - 4.2.7 Testing
15 - 4.2.8 Intermediate measurements
15 - 4.2.9 Recovery
15 - 4.2.10 Cleaning
15 - 4.2.11 Final measurements
15 - 4.2.12 Information to be given in the relevant specification
15 - 4.3 Guidance for test La
15 - 4.3.1 Methods of verification of the degree of protection against ingress of dust into electrotechnical products
16 - 4.3.2 Basic philosophy behind test La, non-abrasive fine dust test
18 - 4.3.3 Methods of generating the test conditions
20 - 4.3.4 Test dust
21 - 4.3.5 Severities of the test
22 - 4.3.6 Reproducibility of the test
23 - 4.3.7 Applicability limits of the test
23 - 4.3.8 Interpretation of results
23 - 5 Test Lb: free settling dust
23 - 5.1 Object
24 - 5.2 Method Lb
24 - 5.2.1 General description
24 - 5.2.2 Description of test apparatus
24 - 5.2.3 Test dust
24 - 5.2.4 Severities
24 - 5.2.5 Preconditioning
25 - 5.2.6 Initial measurements
25 - 5.2.7 Testing
25 - 5.2.8 Intermediate measurements
25 - 5.2.9 Recovery
25 - 5.2.10 Final measurements
25 - 5.2.11 Information to be given in the relevant specification
26 - 5.3 Guidance for test Lb
26 - 5.3.1 Methods of simulation
26 - 5.3.2 Properties and effects of dust in sheltered and enclosed locations
27 - 5.3.3 Basic philosophy behind test Lb, free settling dust
28 - 5.3.4 Method of generating the test conditions
30 - 5.3.5 Severities of the test
31 - 5.3.6 Reproducibility of the test
31 - 5.3.7 Applicability limits of the test
31 - 5.3.8 Interpretation of results
32 - 6 Test Lc: blown dust and sand
32 - 6.1 Method Lc1: recirculating chamber
32 - 6.1.1 Object
32 - 6.1.2 General description of the test
32 - 6.1.3 Description of test apparatus
33 - 6.1.4 Test conditions
35 - 6.1.5 Preconditioning
36 - 6.1.6 Initial measurements
36 - 6.1.7 Testing
36 - 6.1.8 Intermediate measurements
36 - 6.1.9 Recovery
36 - 6.1.10 Cleaning
36 - 6.1.11 Final measurements
36 - 6.1.12 Information to be given in the relevant specification
37 - 6.2 Method Lc2: free blowing dust
37 - 6.2.1 Object
37 - 6.2.2 General description of the test
37 - 6.2.3 Description of test apparatus
37 - 6.2.4 Test conditions
38 - 6.2.5 Preconditioning
38 - 6.2.6 Initial measurements
38 - 6.2.7 Testing
39 - 6.2.8 Intermediate measurements
39 - 6.2.9 Recovery
39 - 6.2.10 Cleaning
39 - 6.2.11 Final measurements
39 - 6.2.12 Information to be given in the relevant specification
40 - 6.3 Guidance for test Lc
40 - 6.3.1 Methods of simulation
40 - 6.3.2 Properties and effects of blown dust and sand
40 - 6.3.3 Basic philosophy behind test Lc, blown dust and sand
41 - 6.3.4 Method of generating the test conditions
44 - 6.3.5 Severity of the test
44 - 6.3.6 Reproducibility of the test
44 - 6.3.7 Applicability limits of the test
44 - 6.3.8 Interpretation of results
51 - Annex A - General guidance
51 - A.1 Characteristics of test dust
53 - A.2 Other dusts
53 - A.3 Effect of humidity on test dust
53 - A.4 Effects on electrotechnical products
55 - A.5 Safety precaution
56 - A.6 Test L and IEC 60529 comparison
59 - Annex B - Bibliography