Isolation and Safety Standards
for Electronic Instruments
IEC 1010 specifies different types of pollution environments. Harsher environments require more insulation. As an alternative to increased insulation, the designer can create a cleaner microenvironment for the circuit. This microenvironment can be created by using enclosures, encapsulation, or hermetic sealing.
Pollution Degree 1 – No pollution or only dry, nonconductive pollution occurs. The pollution has no influence.
Example: A circuit in a hermetically sealed box (such as an IC chip). No air can come into the box to bring condensation or conductive particles.
Pollution Degree 2 – Only nonconductive pollution occurs. Occasionally, temporary conductivity caused by condensation is to be expected.
Example: A circuit used in an office environment. The circuitry inside a computer would fall in this category.
Pollution Degree 3 – Conductive pollution occurs, or dry nonconductive pollution occurs that becomes conductive due to condensation that is to be expected.
Example: Circuitry that is exposed to outside air, but will not be in contact with precipitation.
A garage door opener would fall under this category.
IEC 1010 specifies different types of pollution environments. Harsher environments require more insulation. As an alternative to increased insulation, the designer can create a cleaner microenvironment for the circuit. This microenvironment can be created by using enclosures, encapsulation, or hermetic sealing.
Pollution Degree 1 – No pollution or only dry, nonconductive pollution occurs. The pollution has no influence.
Example: A circuit in a hermetically sealed box (such as an IC chip). No air can come into the box to bring condensation or conductive particles.
Pollution Degree 2 – Only nonconductive pollution occurs. Occasionally, temporary conductivity caused by condensation is to be expected.
Example: A circuit used in an office environment. The circuitry inside a computer would fall in this category.
Pollution Degree 3 – Conductive pollution occurs, or dry nonconductive pollution occurs that becomes conductive due to condensation that is to be expected.
Example: Circuitry that is exposed to outside air, but will not be in contact with precipitation.
A garage door opener would fall under this category.