TECHNICAL BULLETIN TB-3070 Low Resistance Tester Operation and Maintenance Made in the United States of America 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 Figure 1. Desco 19249 Low Resistance Tester 1 Banana Jack Outlet Adapter 1 Certificate of Calibration Description The Desco Low Resistance Tester has three selectable Features and Components test ranges to check resistance paths: <1 ohm, <2 ohms A B C D E F G 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 Figure 2. Low Resistance Tester features and current. The tester defined in ESD STM13.1 provides components a means of checking soldering iron tips while being used. Although the document was written to make A. Selectable Test Ranges: Select the appropriate measurements on soldering and desoldering equipment, range for required test <1 OHM, <2 OHMs, and <10 the measurement techniques can be used for other OHMs. electrical hand tools. The working part of AC powered B. Test Button: Press and hold button to activate the tools should be capable of providing a conductive path tester. to ground. New powered hand tools such as soldering irons typically should have a tip to ground resistance of C. Threaded Banana Plug/Needle Point: Standard Kit less than 1.0 ohm. includes a banana plug and needle point adaptor. NOTE: This resistance may increase with use but should be less than 20.0 ohms for verification D. Audio and Visual Test Indicators: LED and buzzer purposes. Pass result. 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 2015 DESCO INDUSTRIES, INC. TB-3070 Page 1 of 3 June 2015 Employee OwnedE. Low Battery LED: LED illuminates when the battery needs to be replaced. F. 6 Foot Coiled Cord: Insulation black color PVC G. Banana Plug: Industrial Standard .175 (4.4 mm) Banana Plug, fits banana jack .157 . Operation USING THE TESTER 1. Use the slide switch to select a test range. 2. Connect the coil cord banana plug end to known ground. Use adapters where needed. NOTE: The Desco Low Resistance Tester may be used with an outlet polarity checker such as the Desco 19219 to determine a known ground. 3. Connect or touch the tester end to a banana jack or other equipment that is being tested for resistance to ground. 4. Press and hold the test button. 5. An audio and visual indication will activate for a Figure 5. Testing auxiliary ground with the 19249 tester PASS condition. 6. A FAIL condition is indicated when the buzzer does Example of Test Range Uses not sound and the PASS does not illuminate. <1 OHM Range ESD Technical element Grounding Conductors: Banana Jacks, Grounding Blocks, Mat Ground Cords ANSI/ESD S6.1 Grounding, sections 6.4 Technical Elements, 6.4.1, 6.4.2 and 6.4.3 New AC Powered Hand Tools ESD Handbook ESD TR20.20 section 5.5.2.2 Electrical Hand Tools <2 OHM Soldering Irons ESD Handbook ESD TR20.20 section 5.5.2.2 Electrical Hand Tools Other AC Powered Hand Tools ESD Handbook ESD TR20.20 section 5.5.2.2 Figure 3. Testing ground points with the 19249 tester Electrical Hand Tools <10 OHM Soldering iron verification ESD Handbook ESD TR20.20 section 5.5.2.2 Electrical Hand Tools Auxiliary grounds (ground rods) ANSI/ESD S20.20* *ANSI/ESD S20.20 requires <25 ohms from the Auxiliary Ground to the Equipment Grounding Conductor. The Desco Low Resistance Tester only tests to <10 ohms. In cases of a no pass result with the Low Resistance Tester when testing an Auxiliary Ground, an Ohm meter should used to determine the actual resistance from the Auxiliary Ground to the Equipment Grounding Conductor. Figure 4. Testing a soldering iron with the 19249 tester 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 2015 DESCO INDUSTRIES, INC. TB-3070 Page 2 of 3 Employee Owned