DESCO WEST
- 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST
- One Colgate Way, Canton, MA 02021-1407 • (781) 821-8370 • Website:
Desco.com
TB-3070
Page 1 of 3
© 2015 DESCO INDUSTRIES, INC.
Employee Owned
Low Resistance Tester
Operation and Maintenance
Description
The Desco Low Resistance Tester has three selectable
test ranges to check resistance paths: <1 ohm, <2 ohms
and <10 ohms. Per ANSI/ESD S20.20, the required
limit for equipment grounding conductors (such as
banana jacks) is <1 ohm tested per ESD TR53. Per
ANSI/ESD S20.20, the required limit for solder hand
tools is <2 ohms (Product Qualification) and <10 ohms
Compliance Verification tested per ESD TR53. The
Low Resistance Tester is equipped with pass/fail (go/no
go) audio and visual indicators that activate to confirm
that the grounding conductor being tested meets the
required limit. The low battery indicator lets the operator
know when battery needs to be replaced.
ESD Handbook ESD TR20.20 section 5.5.2.2
Electrical Hand Tools
“All electrical tools and equipment used to process ESD
sensitive devices require the three prong, grounded-type
AC plug. The metal portions of the tool that touch the
device should have a low resistance (<2 ohms) to the
equipment ground terminal on the plug. In some cases,
the user may wish to verify that the metal portions of
the tool have acceptable voltage levels and leakage
current. The tester defined in ESD STM13.1 provides
a means of checking soldering iron tips while being
used. Although the document was written to make
measurements on soldering and desoldering equipment,
the measurement techniques can be used for other
electrical hand tools. The working part of AC powered
tools should be capable of providing a conductive path
to ground. New powered hand tools such as soldering
irons typically should have a tip to ground resistance of
less than 1.0 ohm.
NOTE: This resistance may increase with use
but should be less than 20.0 ohms for verification
purposes.”
June 2015
Figure 1. Desco
19249
Low Resistance Tester
ANSI/ESD S6.1 – Grounding
“
6.4.1
The resistance of the conductor from the
groundable point ground of any ESD technical element
(e.g. worksurface, floor, chair, wrist strap, etc.) to the
common point ground or common connection point shall
not be greater than 1 ohm. Where a resistor is used
in the grounding conductor, the total resistance shall
include the value of the resistor.
6.4.2
The resistance of the conductor from the common
point ground to the AC equipment ground shall not be
greater than 1 ohm.”
Packaging
1 Low Resistance Tester
1 Threaded Banana Plug
1 Threaded Needle Point
1 Alligator Clip
1 Banana Jack Outlet Adapter
1 Certificate of Calibration
Features and Components
A. Selectable Test Ranges:
Select the appropriate
range for required test <1 OHM, <2 OHMs, and <10
OHMs.
B. Test Button:
Press and hold button to activate the
tester.
C. Threaded Banana Plug/Needle Point:
Standard Kit
includes a banana plug and needle point adaptor.
D. Audio and Visual Test Indicators:
LED and buzzer
Pass result.
Figure 2. Low Resistance Tester features and
components
A B
C D E
G
F
Made in the
United States of America
TECHNICAL BULLETIN TB-3070
