DESCO WEST
- 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST
- One Colgate Way, Canton, MA 02021-1407 • (781) 821-8370 • Website:
TB-3054
Page 2 of 6
© 2017 DESCO INDUSTRIES, INC.
Employee Owned
ADVANTAGES OF WAVE DISTORTION AND
SINGLE-WIRE TECHNOLOGY
The Desco Multi-Mount Continuous Monitor allows the
use of any standard, single-wire wrist strap and coil
cord. The monitor/wrist strap/cord system life-cycle
costs are by far lower than alternative systems which
require expensive & fragile dual-wire cords and special
wrist straps. Dual-wire cords are expensive and are
the weak link of the system, the most likely component
to need replacement. Over a five year period, this
can make the dual-wire system three to five times as
expensive as a system utilizing single-wire wrist straps
and cords. See Maintenance and Calibration (page 4)
to minimize life-cycle costs.
The dictionary defines constant as uniform and
unchanging, and continuous as uninterrupted.
None theless, some dual-wire resistance monitors
utilize a pulsed test current and do not really provide
continuous monitoring. For example, during each 2.2
second pulse cycle of a leading “constant” resistive
monitor, electrical current is pulsed for only 0.2 seconds
followed by an unmonitored interval of 2 seconds.
This leaves the user/wrist strap unmonitored for over
90% of each cycle. Damaging static charges can
easily occur in the portion of the time in between
the pulses. The off period of 2 seconds equals 2
billion nanoseconds, and “it takes only about 25 volts
applied for 100 nanoseconds to blow most memories
or microprocessors.* The dual-wire system does not
reliably meet all industry specifications, as the cords
do not meet the EOS/ESD S-1.0 paragraph 4.1.6, 1 to
5 pound “breakaway force” requirement for operator
safety.
By using the reliable wave distortion technology to
determine if the circuit is complete, there are no false
alarms. There is no need to adjust or tune the monitor
to a specific user or installation. The miniscule amount
of electrical current (less than 1 volt coil cord signal)
required to generate the waveform has never caused
reported skin irritation and is extremely safe for use
in voltage sensitive applications such as disk drive
manufacturing.
WORKSURFACE CHANNEL
The Multi-Mount Continuous Monitor’s circuitry is
sufficiently sensitive to detect extremely low current,
allowing it to be used with mats having a resistance
of up to 1.0 x 10
7
ohms Rtg. When the Monitor is
connected to an ESD Mat worksurface, the amount of
current that flows is a function of the total resistance
between the monitor and through the worksurface to
ground. When the resistance of the worksurface is
below a pre-set threshold, the monitor will indicate
good. Conversely, if the resistance level is high when
compared to the monitor’s reference, the unit will alarm.
This is an integrating resistance measuring circuit,
therefore it is relatively insensitive to externally induced
electromagnetic fields. The resistance threshold is
factory set to 10 megohms. (It can be special ordered
to other limits. Limits can be varied and set to 100
megohms maximum).
Packaging
Multi-Mount Continuous Monitor, 120VAC
1 Multi-Mount Continuous Monitor
1 24VDC Power Adapter, North America Plug
1 6' Mat Monitor Cord (Black)
1 6' Mat Ground Cord (Green and Yellow)
2 Push and Clinch Snaps
2 Mounting Screws
2 Countersink Washers
1 Set of Hook and Loop Fasteners
1 Zip Tie
1 Certificate of Calibration
Multi-Mount Continuous Monitor, 120VAC
1 Multi-Mount Continuous Monitor
1 24VDC Power Adapter, North America Plug
1
1 6' Mat Monitor Cord (Black)
1 6' Mat Ground Cord (Green and Yellow)
2 Push and Clinch Snaps
2 Mounting Screws
2 Countersink Washers
1 Set of Hook and Loop Fasteners
1 Zip Tie
1 Certificate of Calibration
Multi-Mount Continuous Monitor, 220VAC
1 Multi-Mount Continuous Monitor
1 24VDC Power Adapter without Power Cord
1 6' Mat Monitor Cord (Black)
1 6' Mat Ground Cord (Green and Yellow)
2 Push and Clinch Snaps
2 Mounting Screws
2 Countersink Washers
1 Set of Hook and Loop Fasteners
1 Zip Tie
1 Certificate of Calibration
*1981 article by Donald E. Frank - Electrical Overstress /
Electronic Discharge Symposium Proceedings
