The AMPTEC 620EH Explosive Safety Igniter Tester - High and Low Ohm Ranges

The AMPTEC 620EH Low Resistance Explosive Safety Igniter Tester is a portable digital ohmmeter which has been specifically designed for ultra-safe resistance testing on explosive devices (i.e. squibs, igniters, flares, detonators, warheads).  The 620EH is primarily for indoor lab use, the other AMPTEC 630ES and 640SL (Low Resistance Ruggedized Explosive Safety meter) are ruggedized water proof versions with similar test capabilities.  The AMPTEC 620EH features five way gold panel jacks that directly accept wiring, spade lugs and banana jacks (i.e. with 4 wire Kelvin Clips). For a data sheet of all the accessories, test leads, probes and options that are compatible with the AMPTEC 601ES DMM, 620A-4, 620BH, 620ES, 620GD, 620RK etc select here.  The AMPTEC 620EH has had the unit's circuitry reviewed and approvals are pending by many U.S. Gov. Safety Boards as well as most branches of the armed forces for specific military programs.

High and Low Ohm Range - Accuracy and Resolution

A common question is “What does AMPTEC offer to improve the measurement accuracy and resolution with a low resistance value squib/detonator measurement/application?"  This lead to the development of the AMPTEC 620EH Explosive Safety Igniter Tester.  The 620ES offers the following fullscale ranges - 2.0 Ohms, 20 Ohms, 200 Ohms and 2.0 Megohms.  The 2.0 Ohm fullscale range provides a four-wire Kelvin resistance measurement from 0.0000 ohms to 1.9999 ohms. The 2.0 Ohm range also offers a low (1/10) 0.1 milliohm or 100 microhm resolution.  AMPTEC RESEARCH offers an optional Four Wire Kelvin (OP300) Lead set that eliminates the effects of test lead length resistance and contact resistance errors.

Isolation Testing to 2.0 Megohms

 The 2.0 Megohm range on the AMPTEC 620EH provides a relatively high resistance range for determining open circuit or "electrical isolation between any two contact test points or wires" (>2.00 Megohms) status on ordnance wiring and detonators. See the AMPTEC 620BH or 640SL if you need to measure resistance to 20 Megohms

Incredibly Safer than a commercial DMM

Commercial Multifunction DMM’s have many modes (i.e DC Voltage, AC Voltage, DC current, AC current, frequency, shift keys, Capacitance and more..) that can accidentally mis-measure igniter circuit resistance.  If the DMM has an electrical fault the igniter circuit may accidentally fire.  The 620EH Igniter Tester only measures resistance, it is not a complex multifunction DMM. If the 620ES had an electrical fault it offers the life saving advantage of failing safe.  The lowest Ohm range on most DMMs is 200 Ohms. DMMs also aren't optimized for squib resistance measurements, most squibs are around 1.0 Ohm and the AMPTEC 620EH Explosive Safety Igniter Tester offers a 2.0 Ohm full scale range.

Polyurethane Epoxy Conformal Coated Circuit Board and More ...

A common question we get from safety engineers is "What sort of electrical and  mechanical  measures are taken with the AMPTEC 620ES to prevent an internal  loose wire, metal screw, or washer inside from floating around and shorting the battery output to the terminal output posts?".  The entire PCB (except for the calibration trim pots) is non-conductive polyurethane epoxy coated, to make it extremely difficult to get an accidental conductive pathway.  For starters, the 620ES Explosive Safety Igniter Tester fundamentally uses the USAF Non-Nuclear Safety Board approved AMPTEC 620A-4 Igniter Tester Failsafe ciircuitry.  The 620EH has the added circuitry of the 2.0 Ohm range which has also been approved by the US Dept. of Energy (High Explosive Safety Committee) in the form of the AMPTEC 630ES and AMPTEC 640SL.  The ultimate electrical safety analysis for failsafe current relies on Ohm's Law for determining Imax based upon a Vmax (~ 4.8 VDC battery value) divided by the equivalent circuit current limiting resistance (R-limit) for the particular version being considered.  The AMPTEC 620A circuit schematics are available upon request for reviewing a version's maximum failsafe current level.

Kelvin Clips , Probes and Test Lead Accessories

Optional 24/7 Package

Option 247 allows the 620EH to be safely operated 24 Hrs/Day 7 Days/Week continuously.  It is based upon the same "Hospital Safety Isolation" technology used in monitoring and diagnosing human patients while wired/connected to electrical instrumentation.  This Ultra High Line Isolation DC/DC convertor based option is rated to 3,000 volts isolation.