The Desco 19668 Zero Volt Monitor is a dual workstation continuous monitor. It continuously monitors the path-to-ground integrity of two operators and two ESD worksurfaces. It also will indicate if voltage greater than ±1.25 V is induced onto the operator. Audio and visual alarms activate in failure situations. The Desco Zero Volt Monitor provides stable continuous monitoring of the path-to-ground and presence of two 1 megohm resistors of an operator’s dual-wire wrist strap. Audio and visual alarms activate (in less than 500 milliseconds) when the wrist strap connection points are intermittent.
The Desco Zero Volt Monitor also monitors for a worksurface path-to-ground less than 3.5 megohms. All Desco Zero Volt Monitors are calibrated to NIST standards and include a certificate. A calibration unit is available to preform compliance verification at the workbench without taking the monitor out of service.
DESCO Zero Volt Monitor Technology
The Desco Zero Volt Monitor uses electrical loop resistance technology. Dual test signals are placed onto each of the dual-wire wrist strap's conductors to negate finger-tip voltage. Resistance is monitored with a continuous split test signal sent through both conductors, across the skin of the operator, and returning to the monitor through the opposite conductor.
Desco Zero Volt Monitors determine that the operator’s path-to-ground is between the 2 megohms lower limit and 10 megohms upper limit. Additionally, the Desco Zero Volt Monitor determines if voltage greater than ±1.25 V has accumulated on the operator.