Desco 19212 Installation Manual

TECHNICAL BULLETIN TB-3004

Workstation Continuous Mini Monitor
Operation, Installation, and Maintenance

Advantages Of Continuous Monitoring
Over Periodic Testing:

“When considering constant [or continuous] monitors,
the equipment cost including the wrist strap,
maintenance and training cost, labor time for performing

wrist strap tests, and the potential failures due to

non-functional wrist straps should be considered.

A broken wrist strap may expose products to ESD over

an entire shift if it is checked only at shift change with

wrist strap checker.” (ESD TR 12-01 Section 4.2
Selection Considerations)

®

Workstation Continuous Monitor eliminates

®

Workstation Continuous Mini

®

monitor without the alarm sounding.

®

Figure 1. Jewel

Workstation Continuous Mini Monitor.

Description

The Jewel

independently monitors the operator and the

worksurface. The instant an operator’s wrist strap or
cord fails, the monitor will issue audible and visual
alarms alerting the user of the problem. In the same
manner, the unit also conrms that a path to ground of
less than 500 megohms exists from the ESD

worksurface.

The Jewel® Workstation Continuous Monitor is a Single
Conductor Impedance Sensing Continuous Monitor
which per ESD Handbook TR20.20 section 5.3.9.2.1 “a

small AC voltage is used in a detection circuit designed

to eliminate false alarms and adjustment. They use the
phase difference between current and voltage to detect
changes in impedance of the grounding cord, wristband
and person. No adjustments are required.”

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 monioring should be considered or
even required.”

The Jewel
available in the following model.

Model Color

19212

®

Workstation Continuous Mini Monitor

®

Workstation Continuous Mini Monitor is

Input/Output

Voltage AC

Sapphire 120/24 NIST

Calibration

The Jewel

the need for periodic wrist strap tests and logging.
Continuous monitoring is superior to periodic or pulsed

testing, and can save a signicant amount of money

in testing costs and rejected product. Periodic testing

detects failures after ESD susceptible products way
have been manufactured. The costs of dealing with the
resulting catastrophic or latent defects can be
considerable. Jewel

Monitors eliminate the need for operaters to test wrist

straps and log the results; by their function, these
monitors satisfy the ISO 9000 and ANSI/ESD S20.20
test logging. ANSI/ESD S20.20 Section 6.2.2.2
Personnel Grounding Guidance states “A log should be
maintained which veries that personnel have tested
their personal grounding devices.” Per ANSI/ESD­S1.1 Annex A Section 6.1.3 “Daily (wrist strap system)
testing may be omitted if constant monitoring is used.”
Per ANSI/ESD-S1.1 Annex A 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.”

Park Snap

The audible alarm is designed to alert both operator and
supervisor. The Park Snap feature provides a means

for an operator to disconnect when normally leaving

the work area, without the audible alarm sounding, and
wrist cord storage (visual red LED will illuminate). When
the operator touches the Park Snap, the audible alarm
is disabled for about 8-10 seconds. The operator can

remove the wrist strap cord and attach socket of the

cord to Park Snap for storage. The operator can
separate the coil cord from the wrist band and attach

the coil cord snap to the park snap for convenient

storage. The coil cord may also be removed from the

jack on the Jewel
Once the coil cord is in the park position, the
operator ground status light will remain red.

Made in America

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TB-3004 March 2011 Page 1 of 4

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© 2011 DESCO INDUSTRIES INC.

Employee Owned

Wave Distortion Detection Technology
Provides True 100% Continuous
Monitoring

Wave distortion impedance circuitry monitors current/
voltage phase shifts and provides true 100% continuous
monitoring. Electrical current will lead voltage at

various points due to the combinations of resistance

and capacitive reactance. By monitoring these

“distortions” or phase shifts, the Jewel

®

Workstation

Continuous Mini Monitor will reliably determine if the

circuit is complete.

Wave distortion technology can be referred to as “vector
impedance monitoring”. This description is valid as the

wave distortion technology measures the impedance

at the monitored banana jack and looks for changes in

either the capacitance or resistance of the circuit which

includes the wrist strap and its wearer. It uses
ltering and time domain sampling to lter out false
signals caused by voltage offsets, 60 Hz elds and

other electro-magnetic and electrostatic interference.

In normal factory environments, and with persons

whose capacitance with respect to ground is within

design limits (5 feet tall 90 pound person to 6 foot 5 inch
250 pound person), the Jewel

®

Workstation

Continuous Mini Monitor cannot be “fooled”. It will
provide a reliable alarm only when the wrist strap or
work surface becomes dysfunctional or unsafe
according to accepted industry standards. The Jewel

®

Workstation Continuous Mini Monitor is drift-free and

designed to be insensitive to the effects of squeezing or

stretching the coil cord.

Advantages Of Wave Distortion And
Single-Wire Technology

The Jewel

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 and less durable dual-wire
cords and special wrist straps. The Jewel

Workstation Continuous Mini Monitor is an

economical way to monitor both the operator’s wrist
strap and workstation surface. See “Maintenance and
Calibration” (page 4) to minimize life-cycle costs.

®

Workstation Continuous Mini Monitor

®

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”.*

By using the reliable wave distortion impedance

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 specic 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 Jewel
monitoring circuitry is sufciently sensitive to detect
extremely low current, allowing it to be used with mats
having a resistance of up to 5 x 10E8 ohms RTG.

When the Monitor is connected to an ESD Mat
worksurface, the amount of current that ows 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 elds. The

resistance threshold is factory set to 500 megohms.

(It can be special ordered to other limits. Limits can be
varied and set to 1 gigohm maximum.)

®

Workstation Continuous Mini Monitor

Installation

Conrm that the surface resistance (RTG) of the mat is
5 x 10E8 ohms or less and has a conductive layer. We
recommend the Desco 19780 or 19635 Tester. Remove

the monitor from its packaging and inspect for any

shipping damage. Included with each Jewel
tion Continuous Mini Monitor should be:

1 120 VAC Adapter

2 Push and clinch snaps (09863)

®

Worksta-

The dictionary denes constant as uniform and

unchanging, and continuous as uninterrupted.

Nonetheless, some dual-wire resistance monitors utilize

a pulsed test current and do not 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/

DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone] • Fax [phone]

DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • [phone] • Fax [phone] • Web Site: Desco.com

TB-3004 Page 2 of 4

The Continuous Mini Monitor is normally installed
toward the front edge of a workstation where the LEDs
are easily visible. The unit is designed to be snapped on

the worksurface using the 10mm snap studs mounted at

the bottom of the monitor. See gure 2.

*1981 article by Donald E. Frank - Electrical Overstress /
Electronic Discharge Symposium Proceedings

© 2011 DESCO INDUSTRIES INC.

Employee Owned

ESD MAT

Push & Clinch Socket Snaps

1-5/16"

Location of Push & Clinch
Snaps on work surface

Figure 2. Installation of Push and Clinch Socket Snaps
Figure 3. illustrates how the Monitor is snapped to the

worksurface

Front View of Mini Monitor

Monitors
Worksurface
Connection

The following procedure will outline how to correctly

wire the Jewel® Workstation Continuous Mini Monitor so

as to properly monitor an ESD protected workstation.

1. Conrm that the worksurface surface resistance is 5 x
10E8 Ohms or less and has a conductive layer.

2. A convenient 120 VAC outlet should be located and

tested for proper wiring and grounding. We

recommend Desco Item 98130 AC Outlet Analyzer to

verify proper wiring and ground.

3. Plug the AC Adapter into the outlet and connect the

mini plug into the back side of the Monitor. The green
Worksurface LED should be lit. The Monitor is now
ready for use. If the red Worksurface LED is ashing,

check the snap fasteners for proper connection.

Installation on Micastat® Laminate

Materials Needed:

2 14244 Flush Mount Laminate Ground Inserts
1 14242 Installation Tool for Flush Mount Insert
1 09857 10mm Socket and Rivet (100 per pack)

2 8-32 button cap screws

1. Install the 14244 Flush Mount Inserts in the snap

pattern for the monitor.

2. Once installed, remove the 8-32 screw supplied.

Work Surface

Figure 3. Installing the monitor to the worksurface one
snap at a time

Note: Install the monitor to the worksurface by

aligning one snap at a time and applying a

downward force directly above that snap.

®

Figure 4. Shows the wiring connection for the Jewel
Workstation Continuous Mini Monitor.

ESD MAT

Park

Snap

AC Adapter

Figure 4. Jewel® Workstation Continuous Mini Monitor
setup

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DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone] • Fax [phone]

3. Place a 10mm snap socket on top of the installed
14244 brass insert.

4. Screw the 10mm snap socket into place on the insert
using an 8-32 button cap screw.

5. Do this for both inserts and snap attach the mini

monitor into place; it is now grounded to and
monitoring the Micastat

®

Operation

When the Jewel® Workstation Continuous Mini Monitor

is installed and is connected to an ESD protective work

surface, and it is grounded via an AC adapter cord, the

monitor’s green Worksurface LED and its red Opera-

tor LEDs should be on. The monitor takes 6 seconds to
activate its alarm circuitry when it is rst plugged in.

• The AC adapter must include the ground reference on
the barrel of the output plug.

• The AC adapter therefore supplies the Monitor with

ground.

• The mat resistance is measured between the two
snaps on the bottom of the unit.

• This monitor simplies the workstation, eliminating the

need for a separate mat ground cord.

TB-3004 Page 3 of 4

© 2011 DESCO INDUSTRIES INC.

Employee Owned

To Use The Monitor

1. Plug a wrist strap cord banana plug into the
monitored banana jack on the front of the unit. This

automatically activates the selected operator channel.

The red operator LED should turn on.

2. Remove the charges from your body by making
contact with a properly grounded ESD worksurface.
Snap the cord to the wristband, and t it snugly onto
the wrist. This should silence the audio and cause the
LEDs to switch from red to green. If this does not

happen, check the coil cord for continuity or damage.

Examine the wrist and secure that it has a secure t.
If you have dry skin, apply an approved dissipative

hand lotion such as Menda 35666 Reztore™ ESD

Hand Lotion. When leaving the area, a person

can take the coil cord along or leave it attached to
the monitor in park position. Alarm will shut off in

approximately 8 seconds when operator grounding

cord is removed from unit or will instantly shut off
when cord is parked.

Note: It is recommended that you use the Park Snap

rather than continuously removing the Banana

Plug from its jack. If your process requires the

constant insertion and removal of the Banana

Plug, please contact your Desco Representative

for alternate solutions.

Specications

Test range of monitored circuit 500K - 10M ohms†
Worksurface Limit* Set to 500 Megohms

± 20%

Operating Voltage 24VAC, 50-60 Hz

Wrist strap open circuit voltage 1.2 volts peak to peak
@ 1-2 MicroAmps
Mat test open circuit voltage 5 to 7.5 volts

Response time to alarm <50mS
Operating Temperature 32 - 100ºF
Humidity Range: 0-95% RH, non-

condensing

Size 2.77"L x 2.07"W x
.710"H

† This cannot be veried with standard DC test
equipment. The continuous monitor is an impedance
sensing device and the limits are determined by the

magnitude and angle of the impedance.
* Contact factory for special limits.
Note: Worksurface must have a conductive layer such

as Dual Layer Rubber or Dissipative 3-Layer
Vinyl or Micastat® Dissipative Laminate with
conductive buried layers. Desco Continuous

Monitors are not recommended for use with
homogeneous matting.

Maintenance and Calibration

The Jewel
solid state and designed to be maintenance free. It
is calibrated to NIST traceable standards. There are

no user adjustments necessary. Because of the wave
distortion impedance sensing nature of the test circuit,

special equipment is required for calibration. We recom-

mend that calibration be performed annually using the

Desco 98220 Continuous Monitor Calibration Unit. The

Calibration Unit is a most important product which al-

lows the customer to perform NIST traceable calibration
on continuous monitors. The 98220 is designed to be

used on the shop oor at the workstation, virtually elimi-

nating downtime, verifying that the continuous monitor

is operating within tolerances. The 98220 provides a
simple and quick means to assure compliance verica-

ton Per ANSI/ESD S20.20 Table 3 per ESD TR53.

Limited Warranty

Desco expressly warrants that for a period of one (1) year

from the date of purchase Desco Continuous Monitors

will be free of defects in material (parts) and workmanship
(labor). Within the warranty period, a credit for purchase
of replacement Desco Continuous Monitors, or, at Desco’s
option, the Continuous Monitor will be repaired or replaced
free of charge. If product credit is issued, the amount will
be calculated by multiplying the unused portion of the
expected one year life times the original unit purchase
price. Call Customer Service at 909-627-8178 (Chino, CA)
or 781-821-8370 (Canton, MA) for Return Material
Authorization (RMA) and proper shipping instructions
and address. Include a copy of your original packing slip,

invoice, or other proof of date of purchase. Any unit under

warranty should be shipped prepaid to the Desco factory.
Warranty replacements will take approximately two weeks.

If your unit is out of warranty, Desco will quote repair
charges necessary to bring your unit up to factory
standards. Call Customer Service at 909-627-8178
(Chino, CA) or 781-821-8370 (Canton, MA) for a Return

Material Authorization (RMA) and proper shipping instruc-

tions and address.

Warranty Exclusions

THE FOREGOING EXPRESS WARRANTY IS MADE
IN LIEU OF ALL OTHER PRODUCT WARRANTIES,

EXPRESSED AND IMPLIED, INCLUDING MERCHANT-

ABILITY AND FITNESS FOR A PARTICULAR PURPOSE
WHICH ARE SPECIFICALLY DISCLAIMED. The express

warranty will not apply to defects or damage due to
accidents, neglect, misuse, alterations, operator error, or
failure to properly maintain, clean or repair products.

Limit of Liability

In no event will Desco or any seller be responsible or
liable for any injury, loss or damage, direct or consequent,
arising out of the use of or the inability to use the product.
Before using, users shall determine the suitability of the

product for their intended use, and users assume all risk

and liability whatsoever in connection therewith.

®

Workstation Continuous Mini Monitor is

TB-3004 Page 4 of 4

DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • [phone] • Fax [phone] • Web Site: Desco.com

DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone] • Fax [phone]

© 2011 DESCO INDUSTRIES INC.

Employee Owned