620ES Explosive Safety Igniter Tester- Fail-safe Ohmmeter

Download the Model 620ES datasheet (pdf format)

The 620ES Explosive Safety Igniter Tester
The 620ES 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 620ES is primarily for indoor lab use, the (see model 630ES for the waterproof version). The 620ES features five way gold panel jacks that directly accept wiring, spade lugs and banana jacks (i.e. with 4 wire Kelvin Clips). The 620ES 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.

Fail-safe Design - Built-in Can't Fail Life Saving Features
There are a number of critical military, commercial aerospace and aircraft applications that use squibs, EEDs (electronic explosive devices), detonators, explosive bolts and a number of explosive/blasting devices. It is critically important that these devices detonate when properly triggered. It is also critically important that these devices do not detonate while being tested for wiring continuity/integrity. Each Igniter Tester is manufactured with redundant, dual fail-safe protection - current limiting and resistor network circuitry that limits and ensures that the instrument test currents cannot exceed the specified amount. Even in the unlikely event of a worst case component failure, the output current limiting network is still in effect.

Low Ohm Range - Accuracy and Resolution
A common question asked is "What does Permac offer to improve the measurement accuracy and resolution with a low resistance value squib/detonator measurement/application?". The 620ES offers the following fullscale ranges - 2.0 Ohms, 20 Ohms, 200 Ohms and 200 Kohms. 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. Permac offers an optional Four Wire Kelvin (OP300) Lead set that eliminates the effects of test lead length resistance and contact resistance errors. The 200 Kohm range provides a relatively high resistance range for determining open circuit” (>200 Kohms) status on ordnance wiring and detonators.

Better and Safer than a Multifunction DMM
Multifunction DMM's have many modes (i.e. DC Voltage, AC Voltage, DC current, AC current, frequency, shift keys, Capacitance and more..) that can measure igniter circuit resistance incorrectly. If the DMM has an electrical fault the igniter circuit may accidentally fire. The 620ES 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.

No Hazardous Mercury Batteries
The 620ES does not use hazardous mercury batteries like those in older model igniter testers. All 620ES Igniter Testers are powered with a heavy duty rechargeable Ni-Cad pack for portability purposes. A 120 VAC powered battery charger is standard.

Polyurethane Epoxy Coated Circuit Board and More ...
A common question we get from evaluating safety engineers is "What sort of electrical and mechanical measures are taken with the 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 ohmmeter's output posts are insulated inside the unit with heat shrink tubing covering any of it's conductive surfaces. The entire PCB (except for the calibration trim pots) is also nonconductive polyurethane epoxy coated, to make it extremely difficult to get an accidental conductive pathway. The ultimate electrical safety analysis for fail-safe current relies on "Ohms 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. 620ES circuit schematics are available upon request for reviewing the maximum fail-safe current level.

Specifications
Accuracy: (180 days 25°C ± 10°C) ± 0.02% of reading  ± 0.05% of range for 2.0 ohm range, 0.02% of reading  ± 0.02% of range for 20 ohm through 200 Kohm ranges. Call Permacfor any ranges above 200 Kohms
Display: 4½ digit (19999) L.E.D.  - 20,000 counts (Display visible in direct sunlight (5 times brighter than high intensity LEDs))
Terminal Configuration: Four-wire Kelvin
Overload Indication: Display flashes
Maximum Input: 250 VDC or peak AC without damage
Operating Temperature Range: 0°C to 50°C
Temperature Coefficient: ±.002% per °C (from 0°C to 15°C and 35°C to 50°C)
Conversion Rate: Approximately 3 per second
Power: Rechargeable Ni-Cad batteries (5.0 Ahr) & Charger (115 VAC 50-60 Hz). For Safety Reasons, the 620ES Igniter Tester only allows charging of the units batteries when the main power switch is in the "OFF" position.
Max. Internal Voltage: 4.8 VDC - 4 ea. 1.2 V   Ni-Cads
Size: 235mm/9" D x 254mm/10" W x 76mm/3" H
Weight: 1.6 KG/3.5lbs NET 3 KG/6.5 lbs shipping