Desco 19240 Installation, Operation And Maintenance Manual Download Page 1

DESCO WEST

TB-3017

 Page 1 of 2

© 2022 DESCO INDUSTRIES INC

Employee Owned

Made in the

United States of America

Portable Wrist Strap Tester
Installation, Operation and Maintenance

Description

Per ANSI/ESD S20.20, test equipment is required to 
enact the Compliance Verification Plan Requirement. 
Test equipment shall be selected to make 
measurements of appropriate properties of the technical 
requirements that are incorporated into the ESD 
program plan. The Wrist Strap Tester can be used to 
fulfill ANSI/ESD S1.1, “The wrist strap system should 
be tested daily to ensure proper electrical value” (Annex 
A3). Being a portable battery powered tool, it is perfect 
for small labs or for a supervisor to spotcheck workers 
and/or ensure compliance.

The Desco Portable Wrist Strap Tester is a battery 
operated “on demand” wrist strap tester. When the 
wearer of a wrist strap plugs in their coil cord and 
touches the metallic surface of the Wrist Strap Tester, 
a path for current flow is completed from the wearer’s 
skin, through the wrist strap. This action will cause 
the green “test good” LED to illuminate as long as the 
resistance of the circuit path is between 750 kilohms 
and 10 megohms.

The Desco Portable Wrist Strap Tester and its 
accessories are available as the following item numbers:

Item

Description

19240

Portable Wrist Strap Tester

07010

Calibration Unit

March 2022

Figure 1. Desco 19240 Portable Wrist Strap Tester

Packaging

1  Portable Wrist Strap Tester
1  9V Alkaline Battery
1  Hook and Loop Fastener Strip
1  Certificate of Calibration

Installation

Open the tester’s battery compartment and install 
the included 9V battery. Use the included hook and 
loop fastener strip to mount the tester to a wall or 
worksurface.

NOTE: The low battery indicator flashes briefly every 
time the unit is used. Replace the battery once the 
indicator becomes constant during testing.

Operation

1.  While wearing a wrist strap, plug the wrist cord 

into the wrist strap jack located on the face of the 
Portable Wrist Strap Tester. 

2.  Push down and hold the test switch until the test 

results are displayed. Ensure that your finger also 
makes contact with the metal ring around the 
pushbutton when performing a test. 

 
DO NOT touch any other metal while performing 
your test as this will affect your results. 

3.  A pass test result is indicated by illumination of the 

green PASS LED. A fail low test result is indicated 
by illumination of the red LOW LED. A fail high test 
result is indicated by illumination of the red HIGH 
LED. 

 
If your ESD test fails, check your wrist strap and 
ensure that it is being worn correctly and/or needs 
to be replaced.

NOTE 1: The Portable Wrist Strap Tester may briefly 
display “FAIL HIGH” once the test button is released at 
the conclusion of a test. Residual voltage in the circuit’s 
capacitors causes the test to continue for a split second 
after the button is released. 

NOTE 2: Failures may be caused by dry skin or minimal 
sweat layer. For wrist straps, try using an approved 
dissipative hand lotion such as 

Menda Reztore® ESD 

Hand Lotion

 to your wrist prior to use.

  TECHNICAL BULLETIN TB-3017 

www.calcert.com

[email protected]

1.800.544.2843

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