A PIND test is a Particle Impact Noise Detection test.

According to method 2020.8 of MIL-STD-883

MIL-STD-883

The MIL-STD-883 standard establishes uniform methods, controls, and procedures for testing microelectronic devices suitable for use within Military and Aerospace electronic systems including basic environmental tests to determine resistance to deleterious effects of natural elements and conditions...

, the purpose of a PIND test is to detect loose particles inside an electronics device cavity. The test provides a nondestructive means of identifying those devices containing particles of sufficient mass

Mass

Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...

 that, upon impact within the cavity, excite the transducer

Transducer

A transducer is a device that converts one type of energy to another. Energy types include electrical, mechanical, electromagnetic , chemical, acoustic or thermal energy. While the term transducer commonly implies the use of a sensor/detector, any device which converts energy can be considered a...

.