SMS manufactures an ABL Electrostatic Discharge (ESD) Apparatus for clients who require in-house testing capability to determine the discharge energy required to initiate a sample of explosive.

The primary parts of the test apparatus are a sample cup, a discharge needle, and a capacitor bank to provide the electrical energy. The discharge test area is enclosed in a tight box with a gas sampling infrared detector used to detect reaction byproduct gasses.

An explosive sample is tested by placing it in the sample cup, which is grounded to a base plate. The capacitor bank is charged to 5000 volts. The desired energy is determined by selecting a capacitance value from the capacitor bank. The test is then initiated by dropping the discharge needle rapidly toward the sample. The electrical discharge between the needle and the ground passes through the sample. Initiation is determined by the detection of gaseous reaction products using a LIRA 3000 infrared gas detection apparatus. A level of 40 parts per million is the threshold for a measured reaction.

This test simulates conditions in processing where an electrical discharge could take place as electrostatic energy builds up on process equipment or operators as they move about. Conditions leading to discharge could include lack of appropriate grounding of equipment or use of static generating materials. Solid, liquid, or powdered materials may be tested.

The following are photos of the ABL ESD machine, as manufactured by SMS:

Overall outside view

Switch control panel

Overall view of the needle compartment

Close-up view of the ESD needle, stand,
and sample enclosure