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620A-4 | Digital Failsafe Ohmmeter

The 620A-4 Igniter Tester is a failsafe and portable digital ohmmeter specifically designed for ultra-safe resistance testing on squibs, flares, bridge-wire, and other explosive devices. The 620A-4 safety ohmmeter has been approved by the USAF Non-Nuclear Munitions Safety Board for usage on all non-nuclear munitions, and independently certified to meet Mil. Std. 810 Mtd. 511 for usage in fuel-filled environments. Due to its intense self-safety design and numerous certifications, the 620A-4 failsafe ohmmeter is the industry standard for military programs in need of igniter testing.


Range 20 Ω 200 Ω 2K Ω 20K Ω
Nominal Current 5 mA .5 mA 50 uA 5 uA
Failsafe Current 8 mA 1.5 mA 150 uA 15 uA
Resolution 1 mΩ 10 mΩ 100 mΩ 1 Ω
Accuracy ± .02% of reading & range ± .02% of reading & range ± .02% of reading & range ± .02% of reading & range
Display 4 1/2 digit LED Terminal Banana jack binding posts
Storage Temperature Range -10° to 70° C Operating Temperature Range 0° to 50° C
Dimensions 9.75″ x 10″ x 3.25″ Weight 3 lbs.
Power 4 ea rechargeable 5AHr NICAD batteries Max. Input Voltage 250 VDC
Open Circuit 1.6 VDC Max. Internal Voltage 15 VDC
Update 3 readings/second Temperature Coefficient ± .002% per 1° C
Ordering Information

The 620A-4 failsafe ohmmeter may be purchased as a part of two separate packages, which are listed below.
This product is unavailable for online purchase. For specific pricing information or to place an order for a 620A-4 meter, please contact us today.

Package Description Price
NSN Package Includes 620A-4 failsafe ohmmeter, (OP-100) transit case, (OP-290) leads, (620-DC) battery charger, (OP-430) connector adapter, & U.S. N.I.S.T Calibration Certificate. Request a quote!
Commercial Package Includes 620A-4 failsafe ohmmeter, (OP-300) leads, (OP-401) probes, (OP-110) lead pouch, (620-DC) battery charger, & U.S. N.I.S.T Calibration Certificate. Request a quote!
Lead/Probe Sets The 620A-4 ohmmeter is compatible with our 620 Series probe/lead sets and accessories. This product is also customize-able: it can be rack mounted, contain an RS232C interface, or use an optically isolated power source, for example. Contact us for more information.
Compatible Accessories
Part Number Description Link Price
620-DC Battery Charger for 620 Series Igniter Testers Click Here $150.00
620-BAT Set of 4 NiCd D cell batteries Click Here $95.00
OP-100 Transit Case Click Here $175.00
OP-290 4′ Alligator Clip Lead Set Click Here $160.00
OP-300 4′ Gold Plated Kelvin Clip Lead Set Click Here $160.00
OP-304 4′ Banana Jack Calibration Lead Set Click Here $265.00
620 Series Leads The 620A-4 is compatible with our 620 Series probes and leads Click Here