AMPTEC Research · Intrinsically Safe Igniter Testers
620BH
Ultra-safe failsafe ohmmeter for initiator bridge wires and explosive devices
The AMPTEC 620BH is a portable digital ohmmeter made for squibs, flares, bridge wires and other explosive devices. A failsafe current-limiting resistor network keeps the test current below 8 mA at all times. Derived from the 620A-4 design approved by the USAF Non-Nuclear Munitions Safety Board, it measures from 2 Ω to 20 MΩ with high accuracy and is a standard choice for ignition circuit testing in aerospace, defense and ordnance work. Evencat is the sole distributor for AMPTEC Research in Taiwan.
Overview
The 620BH is the mid-range member of the AMPTEC 620 series of intrinsically safe igniter testers, built for ultra-safe resistance checks on explosive devices. Its core is a failsafe current-limiting resistor network that caps the test current at 8 mA, so an internal fault cannot fire the initiator or bridge wire under test. Four ranges cover 2 Ω, 200 Ω, 200 KΩ and 20 MΩ, read out on a 4 1/2 digit LED display at 3 readings per second; on the 2 Ω range you get ±0.02% of reading accuracy and 100 µΩ resolution. The design descends from the 620A-4 approved by the USAF Non-Nuclear Munitions Safety Board, is UL-913 compliant and built under ISO 9001:2015, and takes the OP-232 RS232C interface for data capture. Each unit is made in the USA and ships with a one-year warranty and an N.I.S.T. calibration certificate with data. Before ordering, check which Kelvin leads suit your terminals and whether you want the OP-247 AC module for a fixed station.
Key specifications
| Resistance ranges | 2 Ω / 200 Ω / 200 KΩ / 20 MΩ |
|---|---|
| Failsafe maximum test current | 8 mA |
| Nominal test current | 5 mA on the 2 Ω range; 0.5 mA / 0.5 µA on the 200 Ω / 200 KΩ ranges |
| Accuracy | 2 Ω range ±0.02% of reading ±0.05% of range; 20 MΩ range ±2% of reading |
| Resolution | 100 µΩ on the 2 Ω range |
| Display | 4 1/2 digit LED |
| Update rate | 3 readings per second |
| Open-circuit voltage | 1.6 VDC |
| Maximum internal voltage | 4.8 VDC |
| Power | 4 rechargeable 5 AHr NICAD batteries |
| Operating / storage temperature | 0°–50°C / –10°–70°C |
| Dimensions / weight | 9.75" × 10" × 3.25" / 3 lbs |
Features
Failsafe current-limiting circuit
A built-in current-limiting resistor network keeps the test current below 8 mA under all conditions, so squibs, flares and bridge wires can be tested safely.
Wide measurement span
Four ranges from 2 Ω to 20 MΩ cover low-resistance bridge wires through to insulation checks; the 2 Ω range delivers ±0.02% of reading accuracy and 100 µΩ resolution.
4 1/2 digit LED display
A clear 4 1/2 digit LED readout updated 3 times per second gives fast, accurate resistance values on the bench and in the field.
Portable battery power
Runs on 4 rechargeable 5 AHr NICAD batteries and weighs only 3 lbs, so it moves easily between production lines, magazines and field sites.
RS232C data interface
With the OP-232 RS232C interface, readings go straight to a PC for logging, traceability and automated test sequences.
Military approval and certifications
Derived from the 620A-4 design approved by the USAF Non-Nuclear Munitions Safety Board, UL-913 compliant, built under ISO 9001:2015 and made in the USA.
Typical applications
Aerospace ground test
Bridge-wire verification on rocket motors and satellite release mechanisms
During pre-launch ground preparation, technicians use the 620BH to confirm the resistance and continuity of motor igniter bridge wires and the squibs in satellite separation mechanisms. It shows whether a lead is open or shorted while holding the test current well below the firing threshold, so an accidental ignition cannot injure people or damage hardware.
Munitions maintenance
Routine electrical safety checks on non-nuclear munitions and flares
Following procedures recognized by the USAF Non-Nuclear Munitions Safety Board, armorers in storage areas and field settings use the 620BH to sample the bridge-wire resistance of flares and initiators. Resistance drift from aging, moisture or mechanical damage shows up early, so the munition can be relied on to fire when needed. The meter also meets MIL-STD-810F environmental requirements.
Industrial hazardous areas
Live maintenance of ignition systems inside ATEX hazardous areas
In petrochemical plants, mines and other flammable gas or dust environments (EU ATEX EEX-9B-IIC-T4 rated sites), maintenance engineers must check the circuit integrity of industrial igniters without shutting the process down. The intrinsically safe 620BH (UL-913 Listed) can be taken straight into the classified zone with no extra isolation equipment, cutting maintenance downtime and risk.
Options and configuration
Tick the options you need. We compile the configuration into a list and carry it into the quote form.
Standard equipment (included)
Hardware options
Test lead / probe options
Downloads
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