Dust and Sand Test

The dust and sand test is structured into three groups in standard IEC60068-2-68:

La: non-abrasive fine dust. A test which is primarily oriented towards investigation of the seals of the test specimen. The test specimen is exposed to a very fine dust in the form of talc or an equivalent. The effects of temperature cycling resulting in a pressure difference between the inside and outside of the specimen may be reproduced.

Lb: Free setting dust. A test which is oriented towards investigation of the effects when simulating conditions at sheltered locations. The test specimen is exposed to a low-density dust atmosphere created by the intermittent injection of a small quantity of dust which is allowed to fall by gravity onto the specimen.

Lc: Blown dust and sand. A test which is oriented towards investigation of the seals and the effect of erosion when simulating outdoor and vehicle conditions. The test specimen is exposed to either a turbulent or a laminar air flow to which is added a quantity of dust, sand or a dust/sand mixture.

Procedure	Dust/sand type	Particle size	Dust/sand concentration	Notes
Test La
Method La1	Talc or FE powder	<75μm	600g/m2/h , deposit on reference surface	Test includes a cycling of the air pressure in the chamber
Method La2		<75μm	2kg/m3 (chamber volume)	Air pressure in the specimen may be reduced
Test Lb	Olivine or quartz or feldspar	<75μm	6g/m2/d, deposit on reference surface	Free settling dust
Test Lc
Method Lc1	Olivine or quartz or feldspar	<75μm or <150μm or <850μm	1g/m3 or 3g/m3 or 10g/m3	Blown dust and sand recirculating chamber
Method Lc2				Free Blowing dust

 

See from the definition, the dust chamber designed according to IEC60529 can perform the dust test as per proposed method La2. The object of this test is to determine the degree of protection against ingress of find dust into electrotechnical products (IP5X and IP6X). Method La2 is a dust tightness test in which the specimen is exposed to a heavily dust-laden air flow containing non-abrasive power of particle size＜75μm, a vertical downwards air flow is specified for the test. The specified quantity of power (2kg/m³) ensures that the dust concertration is extremely high and uniform.