EMIT - 3651 Walnut Avenue, Chino, CA 91710 • (909) 664-9980 • Website: DescoEMIT.com
TB-6515 Page 1 of 6 © 2017 DESCO INDUSTRIES, INC.
Employee Owned
Zero Volt Monitor
Installation, Operation and Maintenance
Description
The EMIT Zero Volt Monitor using ZERO VOLT
MONITORING™ resistive loop technology meets ANSI/
ESD S20.20 conitinuous monitoring requirements,
continuously veries the proper resistance to ground
of the operator and worksurface [or other item at the
workstation] and will detect charge accumulation on the
operator. It is to be used with dual-wire wrist straps (not
included). Zero Volt Monitoring sends two test signals
which are of equal and opposite polarity. The result
is near zero voltage being placed on the operator with
respect to equipment ground. The Zero Volt Monitor is
also unaected by capacitance variations associated
with personnel and environmental conditions. Dual-Wire
Continuous Monitors provide redundancy; even if one
dual-wire wrist strap conductor is severed, operator has
reliable path-to-ground with other wire. The steady state
DC test signal will detect intermittent failures that may
be missed by pulsed DC systems. An EMIT Calibration
Unit is available so proper compliance verication per
ESD TR53 can be performed at the workbench without
taking the monitor out of service. Each Zero Volt Monitor
is calibrated within accepted procedures and standards
traceable to the National Institute of Standards and
Technology (NIST) and includes a NIST certicate.
Per ANSI/ESD S1.1 section 6.1.3 Frequency of
Functional Testing “The wrist strap system should be
tested daily to ensure proper electrical value. Daily
testing may be omitted if constant monitoring is used.”
Per ESD Handbook ESD TR20.20 section 5.3.2.4.4
“Typical Test programs recommend that wrist straps that
are used daily should be tested daily. However, if the
products that are being produced are of such value that
knowledge of a continuous, reliable ground is needed,
and then continuous monitoring should be considered or
even required.”
Per ESD Handbook ESD TR20.20 section 5.3.9.2.2
Dual Conductor Resistance Continuous Monitors “This
type of monitor is used with a two wire (dual conductor)
wrist strap. The wrist strap assembly consists of a
two-wire ground cord and a wristband that has two
isolated halves. When a person is wearing the wrist
TECHNICAL BULLETIN TB-6515
October 2017
strap properly, the monitor measures the loop resistance
consisting of one wire of the ground cord, one-half of
the wristband, the person’s skin, the second half of the
wristband, and a second wire in the ground cord. If any
part of the loop should open (become disconnected or
have out of limit resistance), the circuit will go into alarm
state” nonetheless, due to the redundancy inherent
in the dual-wire wrist strap design, the operator will
continue to be grounded via the second intact wire.
The Zero Volt Monitor is available in the following
models:
Packaging
1 Zero Volt Monitor
1 Snap Kit
1
Power Adapter (50528, 50538 only)
2 Wrist Strap Kits
2 Operator Cables (black and white)
2 Mat Cords (black and white)
1 Monitor Ground Cord (green)
2 Mat Ground Cords (green)
Features and Components
Figure 1. EMIT Zero Volt Monitor Item Power Adapter Wrist Strap Kit
50528 N. America 19690
50537 None 19690
50538 N. America 09163
A B C D E
FRONT VIEWF G
BACK VIEW
H I J K LMN O P
Figure 2. Zero Volt Monitor features and components
Made in the
United States of America
