3M Wrist Strap and Ground Monitor 773 User manual

3M™Wrist Strap
and Ground Monitor 773
User’s Guide

2
Table of Contents
Safety Information................................................................................................................. 3
1.0 Description ...................................................................................................................... 6
Overview............................................................................................................................................. 6
Performance ....................................................................................................................................... 7
2.0 Installation....................................................................................................................... 8
Supplied Parts..................................................................................................................................... 8
Wire Attachment ................................................................................................................................. 8
AC/DC Adapter Connection.................................................................................................................. 8
Mounting ............................................................................................................................................ 8
3.0 Specifications................................................................................................................ 10
4.0 Enabling or Disabling Monitoring of Ground Lines....................................................... 11
5.0 Setting Impedance Alarm Levels..................................................................................12
6.0 Verification Check ......................................................................................................... 14
7.0 Functional Operations...................................................................................................15
Ground Resistance Monitor............................................................................................................... 15
Person Voltage and Resistance Monitor ............................................................................................ 15
8.0 Accessory Items............................................................................................................ 17
Replacement and Removing Input Wriststrap Dual Conductor Input Jack ......................................... 17
9.0 Customer and Technical Service .................................................................................. 18
10.0 Regulatory Information............................................................................................... 18

3
EXPLANATION OF SIGNAL WORD CONSEQUENCES
WARNING:
Indicates a potentially hazardous situation, which, if not
avoided, could result in death or serious injury and/or
property damage.
CAUTION:
Indicates a potentially hazardous situation, which, if not
avoided, may result in minor or moderate injury and/or
property damage.
NOTICE: Indicates a potentially hazardous situation, which, if not
avoided, may result in property damage.
Safety Information
Read, understand, and follow all safety information contained in this user guide
prior to installation and use of the 3M™Wrist Strap and Ground Monitor 773.
Retain this guide for future reference.
Intended Use
This user guide covers the Wrist Strap and Ground Monitor 773. The 773 monitor
has two input jacks for monitoring impedance and voltage on a dual conductor
wriststrap. It monitors either one or two metal grounds in a workstation. The monitor
operates from a universal AC power adapter. These systems are typically installed on
a machine with multiple tools or on a work bench used for ESD-sensitive electronic
assembly or repair.
The systems must be installed as specified in this user’s guide and are intended for use
in an indoor commercial/industrial environment. The systems have not been evaluated
for other uses or locations.

4
EXPLANATION OF PRODUCT SAFETY
LABEL SYMBOLS
Warning: Read User’s Guide
Warning: Hazardous Voltage
WARNING:
To reduce the risks associated with hazardous voltage, which if not avoided could
result in electrical shock related injury; the risks associated with environmental
contamination, which if not avoided could result in environmental contamination
related injury; and the risk associated with false test results, which if not avoided
could result in property damage:
• Read, understand and follow all safety information contained in this user guide for
installation and use. Retain this guide for future reference
To reduce the risks associated with hazardous voltage, which if not avoided could
result in electrical shock related injury:
• Replace power adapter if damaged with 3M-provided power adapter only
• Do not modify or attempt to service the power adapter or use it if damaged
• Use the power adapter in an indoor dry location only
Other Conventions:
Important Note
It is strongly recommended that you pay attention to information identified as an “Important Note”.
Note: You may find information identified as a “Note” helpful.

5
CAUTION:
To reduce the risks associated with environmental contamination, which if not
avoided could result in environmental contamination related injury:
• Dispose of the monitor and power adapter in accordance with local, state, and federal
regulations.
NOTICE:
To reduce the risks associated with property damage:
• Monitor must be checked periodically to verify each monitor circuit is functioning
correctly
• The 3M™Wrist Strap and Ground Monitor 773 requires a suitable ground to function
properly. Refer to the proper section of this User Guide for information on connecting
to a suitable electrical ground point
• Do not use the Monitor 773 as a primary method of electrical grounding – this device
is intended to monitor the ground connection only
FCC Information
This device complies with Part 15 of the FCC Rules. Operation is subject to the following
two conditions: (1) this device may not cause harmful interference, and (2) this device must
accept any interference received, including interference that may cause undesired operation.
Note: This equipment has been tested and found to comply with the limits for a Class A digital
device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable
protection against harmful interference when the equipment is operated in a commercial
environment. This equipment generates, uses, and can radiate radio frequency energy and,
if not installed and used in accordance with the instruction manual, may cause harmful
interference to radio communications. Operation of this equipment in a residential area is
likely to cause harmful interference in which case the user will be required to correct the
interference at his own expense.
Industry Canada Information
This Class A digital apparatus complies with Canadian ICES-003.

6
1.0 Description
Overview
The 3M™Wrist Strap and Ground Monitor 773 can be used in work areas or other
locations to monitor the ground impedance of metal ground connection in process
tools in semiconductor, disk drive, flat panel, electronic equipment manufacturing and
other environments. Ground impedance monitoring can be used for up to two points
for metal ground, such as within a tool. The 773 monitor can be used to monitor
the impedance-to-ground and voltage level on two persons wearing dual-wire wrist
straps. The unit incorporates green and red LEDs and an audible alarm, as well as an
output logic signal to a host equipment.
Ground Impedance Monitor—Continuously monitors for ground impedance on one
or two separate channels that are connected to one or two process tools. The alarm
level is set the same for all channels.
Output Signal—An output signal is available for connecting to the tool’s computer
or PLC. The 5V signal is either logic 1 or 0 for indicating the monitored ground
resistance/impedance conditions and for the wrist strap.
Operator Connection
The 773 monitor provides continuous monitoring of operator connection to the
monitor via loop resistance check of operator’s physical presence using a dual-
wire wrist strap.
Voltage on Person Wrist Strap Monitor—The 773 monitor has one additional
feature that allows continuous monitoring for excessive voltage on each operator.

7
Performance
Ground Impedance Alarm Level—The alarm level can be preset from 1 to 10 ohms
in step of 1 Ohm and from 10 to 20 ohms (in steps of 2 Ohms) by using the Set switch
and by selecting through a combination of LED patterns indicated on the front of the
unit. All two monitoring lines are set to the same selected impedance value. If the
measured impedance on a line is lower than the setting, a green LED will remain
illuminated for that line(s). If the impedance is higher than the preset level, a red
LED and audible alarm are activated for that line(s). Their alarm duration will be
on for at least 0.5 second to prevent missing a short increased resistance event. If the
impedance level remains above the preset alarm level, the red LED and audible sound
remains on.
Note: A wire must be attached from the 3M™Wrist Strap and Ground Monitor 773
(GND terminal) to an approved ground point to monitor the grounding of process
tools correctly.
Output Signal Level—The output connector provides a logic 1 (+5V) when all
grounds are within limits and the unit is powered on. If any of the monitored grounds
fail or a wriststrap fails, or power to the unit is lost, the output is logic 0 (0V).
Person Voltage and Resistance Monitor—The alarm level is monitored when a
person is wearing a dual conductor wrist strap assembly and plugged into the front
jack. There is a short hold on the body voltage alarm so that it is not missed. The unit
will respond to either a positive or negative voltage. The alarm is activated when the
wrist strap is worn too loosely and the loop resistance level is exceeded. The red LED
indicates over the resistance limit without a voltage being generated on the person at
the same time. The green LED indicates a proper connection of the operator. A green
LED plus a blinking red LED will indicate if there is a body voltage generated; the
operator may still be connected properly. The green LED is off when a dual conductor
ground cord is not plugged into the jack.
Enabling and Disabling Audible Alarm—The audible alarm can be enabled or
disabled by momentarily pressing a recessed miniature push-button “Set” switch
located on the back of the unit while the monitor’s power is on. Use an unbent paper
clip to press the switch. One short beep on power up means that the sound is disabled;
A series of two short beeps means that the sound is enabled.

8
Section 2.0 Installation
Supplied Parts
The 3M™Wrist Strap and Ground Monitor 773 is supplied with the following items:
User’s Guide, AC/DC Adapter
Wire Attachment
Attach 18 AWG wires to the unit as described
below. Strip back the vinyl insulation at each
end of the wires to approximately ¹/³inch
(8 mm). Twist the stranded wire on each end
before inserting the wire into each connector
location. In order to attach the wire, insert a small blade screwdriver into the orange
slot above. Gently push inward and insert the stripped wire fully into the hole in the
green connector. Hold the wire fully in and release the screwdriver to allow the wire
to catch.
Attach the ground wire to the “GND” connector on back of unit.
Attach the impedance monitor wire(s) to the chosen ground lines “G1, G2”
connector(s) on the back of the unit. Insert the wire as described above.
If you are planning to use the 773 monitor output to the tool, attach the wire to the
“Out” connector on the back of the unit. Insert the wire as described above.
AC/DC Adapter Connection
Connect the circular plug of the AC/DC Adapter into the power jack on the back of
the unit.

9
Mounting
Determine the mounting location of the 3M™Wrist Strap and Ground Monitor 773
unit.
Attach the unit using one of the following recommended methods:
• Screws
• 3M™Dual Lock™Reclosable Fastener
Note: The unit can be mounted upside down from the current orientation of the front
and back covers. If you wish to change the orientation, rotate the printed circuit
board and covers 180 degrees. This will allow the unit housing to be mounted from
the wider plate with screw slots.
Undo the screws on the back and front panels using a Philips screwdriver #1, pull out
the internal board with the wrist strap jack attached, flip it 180 degrees, insert it back
into the enclosure and reattach the lids in new orientation.

10
Parameter Typical Value or Function
Ground Impedance Alarm Level 1 to 20 Ohms
Wrist Strap Alarm
Body Voltage
Operator Loop Resistance
+/-5 Volts on operator
10 Megohms on operator (plus two 1 Megohm
resistors in the end of the ground cord that
attaches to the wrist band)
Output Signal Level Logic 1 (+5V) if below selected resistance level
(all “pass”)
Logic 0 (0V) if above selected resistance level
(any failure or power loss)
Note: This is for both process tools and wrist
strap monitoring.
Alarm Indicators
Visual Indication (LED)
Audible
Green OK, Red Fault Condition
Note: Operator LEDs red or green will not
illuminate if wrist strap is not plugged into jack.
Buzzer fault condition if enabled is ON.
Operating Environmental Range Temperature: 50°F, (10°C) to 110°F (43°C)
Humidity: 75% R.H. Maximum
Dimensions 2.4 in. W x 0.85 in. H x 2.25 in. L
61 mm x 22 mm x 59 mm
AC/DC Adapter
US 120VAC, 60Hz
Universal 100 - 230VAC 50 - 60Hz
Output: 12VDC @500 mA
Output Plug Polarization: Center Positive
Output Plug: 5.5 mm O.D. x 2.1 mm I.D. x
2.1 mm x 9.5 mm length
Section 3.0 Specifications
3M™Wrist Strap and Ground Monitor 773

11
Section 4.0 Enabling or Disabling
Monitoring of Ground Lines
In some instances, both of the two ground points in the tool do not need to be
monitored. This procedure will set up the number of ground lines (G1, G2) that
will be used, so that there is no need to put jumpers or shunts on the unused ground
monitoring inputs. The AC Adapter should not be plugged in at this time.
Attach the “GND” line to ground.
Attach the monitor line(s) (G1, G2) to the ground that has been determined to use. Do
not plug any wires into those ground monitor inputs that will be unused.
Press and hold the “Set” button using the unbent end of a paper clip. While the button
is pressed inward, plug in the AC Adapter and then release the “Set” button.
Wait then for ~30 seconds. The 3M™Wrist Strap and Ground Monitor 773 will beep
during this time. After this, it will produce one beep and will automatically disable
the lines to which nothing was connected. You can repeat this procedure whenever a
change in monitoring of the number of ground lines is required.
Enabling and Disabling Audible Alarm—The audible alarm can be enabled or
disabled by momentarily pressing a recessed miniature push-button “Set” switch
located on the back of the unit while the monitor is power on. Use an unbent paper
clip to press the switch.

12
Section 5.0 Setting Impedance
Alarm Levels
By default, the 3M™Wrist Strap and Ground Monitor 773 is set at the factory to
10 Ohms alarm level.
If you wish to change this alarm level to your specification, follow this procedure to
set the impedance alarm level for all channels (G1, G2).
Repeat the steps above in Section 4.0.
Right after the beeping stops, continue pressing the “Set” button until the impedance
level is matched as shown in the table on page 13.
When the beeping stops, the left most four LED allow for setting of resistance value.
G1 & G2 red LEDs are upper location and G1 & G2 green LEDs are lower. Select
the ground resistance value by repeatedly pressing the “Set” button to advance the
resistance limit. This will turn the LEDs on or off as indicated in the table on the
following page.
Not pressing the “Set” switch for about seven seconds after selecting causes the limit
value to be saved and normal operation started.

13
Using LEDs on Front of Unit to
Set Resistance Alarm Level
Resistance
Ohms
LED Resistance
Ohms
LED
1 9
2 10
3 12
4 14
5 16
6 18
7 20
8

14
Section 6.0 Verification Check
Equipment Required:
For this test, the 3M™Wrist Strap and Ground Monitor
773 should be disconnected from the monitored
grounds.
Use the 3M™Workstation Monitor Checker CTE701.
Connect the ground input of the checker to the ground
terminal of the 773 monitor. Set the checker to a
proper resistance alarm level (see the Workstation
Monitor Checker CTE701 User’s Guide). Connect
the red tip of the checker to the ground monitoring
terminal (i.e. G1, or G2). Press the Fail button on the
checker. The red LED of the corresponding ground
of the monitor should remain on. Press the Pass
button on the checker—the corresponding light on the
monitor should be green. Repeat these steps for all
enabled ground monitoring inputs.
The checker verifies the proper operation of dual wrist strap monitoring. Connect
a 3.5 mm test cable to both the checker and to the operator jack of the monitor. At
this point the monitor should indicate failure. Depress the Pass button on the wrist
strap section. The monitor should indicate a good connection. While pressing the
Pass button, press body voltage “high.” At this point the Wrist Strap LED would be
blinking red.

15
Section 7.0 Functional Operations
Ground Resistance Monitor
Connect the ground wire to a known good electrical ground point.
Connect the output wire to the tool if you intend to use it, otherwise leave it open.
Connect the ground monitor inputs to the identified locations. Be sure to connect
the monitoring inputs to different physical locations than those points used for
their grounding.
Person Voltage and Resistance Monitor
Plug the dual conductor ground cord of the wrist strap into the jack on the front of
the unit. If the wrist strap is worn properly, a green LED will come on; otherwise red
LED will be on. In order to provide good ground connection, the wrist strap must be
worn tightly and the green light on the 3M™Wrist Strap and Ground Monitor 773 is
an indication of that.
If for whatever reason, while properly connected, the operator developed excessive
body voltage (in excess of 5V in any polarity), the green LED may still be on, but the
red LED will blink without alarm sound.
No LED is on if a dual conductor ground cord is not plugged into the jack.

16
Connecting the 3M™Wrist Strap and
Ground Monitor 773 Unit

17
Section 8.0 Accessory Items
Use of a dual conductor wrist strap system allows for monitoring a person
continuously while they are being grounded. It allows for the voltage and resistance to
be measured simultaneously. If any fault condition is noticed, a person can stop and
locate the cause for insufficient grounding of the person. This will prevent possible
further damage to the components, printed circuit boards or equipment they are
working on.
Replacement and Removing Input Wrist Strap Dual
Conductor Input Jack
If the wrist strap input jack begins to show wear after heavy usage, the input jack can
be replaced by ordering input jack part number above. Remove the input jack in the
unit by removing the locking collar and two screws on front cover. Slide the printed
circuit board outside of the unit and unplug the pin connector with input jack board.
Plug in new input jack board assembly and carefully slide the board back into the
housing. Replace front cover and locking collar on the input jack.
3M Product Number Description
2368 Dual Conductor Fabric Adjustable Wrist Band
2360 Dual Conductor Coiled Ground Cord, 5ft.
2370 Dual Conductor Coiled Ground Cord, 10ft.
3M™Workstation Checker CTE701 Workstation Monitor Checker
APD12X Dual Conductor Input Jack Board Replacement

18
Section 9.0 Customer and
Technical Service
For customer and technical support within the US:
Contact 3M Electronic Solutions Division, Customer Service Department
866-722-3736
For customer service and technical support outside the US:
Contact: [e-mail]
Contact: John Vallinan ([e-mail])—Asia Pacific
3M™Wrist Strap and
Ground Monitor 773
Regulatory Information
China RoHS
Electronic Industry Standard of the People’s Republic of China, SJ/T11363-2006,
Requirements for Concentration Limits for Certain Hazardous Substances in
Electronic Information Products.
This symbol, per Marking for the Control of Pollution Caused
by Electronic Information Products, SJ/T11364-2006, means
that the product or part does contain a substance, as detailed in
the chart below, in excess of the following maximum concentration
values in any homogeneous material: (a) 0.1% (by weight) for lead, mercury, hexavalent
chromium, polybrominated biphenyls or polybrominated diphenyl ethers; or (b) 0.01%
(by weight) for cadmium. Unless otherwise stated by 3M in writing, this information
represents 3M’s best knowledge and belief based upon information provided by third
party suppliers to 3M.

19
This numerical reference should not be construed as a representation regarding the product’s
life or an extension of a product warranty. In the event any product is proven not to conform with
3M’s Regulatory Information Sheet, then 3M’s entire liability and buyer’s exclusive remedy, will
be at 3M’s option either: (i) replacement of product with a conforming product, or (ii) refund of
the purchase price paid by buyer for each non-conforming product, within a reasonable time after
written notification of said non-conformance and return of said product to 3M. 3M shall not under
any circumstances be liable for direct, incidental, special, or consequential damages (including
but not limited to loss of profits, revenue, or business) related to or arising out of this certification,
including, the use, misuse or inability to use the product. Unless stated otherwise in writing, the
foregoing language cannot be waived, modified, or supplemented in any manner whatsoever.
产品中有毒有害物质或元素的名称及含量
Name and Content of Hazardous Substances or Elements
部件名称
(Part or Component Name)
有毒有害物质或元素
(Hazardous Substances or Elements)
铅
(Pb)
汞
(Hg)
镉
(Cd)
六价
铬Cr(VI)
多溴联
苯 (PBB)
多溴二苯
醚(PBDE)
0603电阻引脚
(Terminations in resistors 0603)
× ○ ○ ○ ○ ○
0603阻电镀部
(Plating in resistors 0603)
×○ ○ ○ ○ ○
装置的焊接部
(Solder in instrument)
× ○ ○ ○ ○ ○
○：表示该有毒有害物质在该部件所有均质材料中的含量均在
SJ/T11363-2006 标准规定的限量要求以下。(Indicates that this hazardous substance
contained in all of the homogeneous materials for this part is below the limit requirement in SJ/T11363-2006.)
×：表示该有毒有害物质至少在该部件的某一均质材料中的含
量超出SJ/T11363-2006 标准规定的限量要求。(Indicates that this hazardous substance
contained in at least one of the homogeneous materials used for this part is above the limit requirement in SJ/
T11363-2006.)”

Please recycle. Printed in U.S.A.
© 3M 2009. All rights reserved.
78-9100-7843-1
Electronic Solutions Division
Static Control Products
6801 River Place Blvd.
Austin, TX 78726-9000
866-722-3736
www.3Mstatic.com
Important Notice
All statements, technical information, and recommendations related to 3M’s products are based on information
believed to be reliable, but the accuracy or completeness is not guaranteed. Before using this product, you must
evaluate it and determine if it is suitable for your intended application. You assume all risks and liability associated
with such use. Any statements related to the product which are not contained in 3M’s current publications, or any
contrary statements contained on your purchase order shall have no force or effect unless expressly agreed upon,
in writing, by an authorized officer of 3M.
Warranty; Limited Remedy; Limited Liability.
This product will be free from defects in material and manufacture for a period of one (1) year from the time of
purchase. 3M MAKES NO OTHER WARRANTIES INCLUDING, BUT NOT LIMITED TO, ANY IMPLIED WARRANTY
OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
If this product is defective within the warranty period stated above, your exclusive remedy shall be, at 3M’s option,
to replace or repair the 3M product or refund the purchase price of the 3M product. Except where prohibited by
law, 3M will not be liable for any indirect, special, incidental or consequential loss or damage arising from
this 3M product, regardless of the legal theory asserted.
3M and Dual Lock are trademarks of 3M Company.