AMPTEC Research · Intrinsically Safe Igniter Testers
620VL
Intrinsically safe igniter resistance tester for devices with a series diode
The 620VL is the AMPTEC igniter tester to specify when the explosive device carries a diode in series with the bridge-wire, a case a plain ohmmeter reads wrongly or not at all. It pairs a 4-1/2 digit LED display with 4-wire Kelvin terminals and measures across four ranges from 2 kohm to 2 Mohm. Failsafe current limiting on every range and an intrinsically safe architecture mean a detonator, flare or bridge-wire cannot be fired by the test. Defense, aerospace and launch-system laboratories in Taiwan use it for exactly that reason. Evencat is the sole distributor for AMPTEC in Taiwan.
Overview
The AMPTEC 620VL is an intrinsically safe igniter tester designed for resistance measurements on explosive devices that include a series diode, so detonators, flares and bridge-wire assemblies with protective diodes can be checked safely and read clearly. It uses a 4-1/2 digit LED display and 4-wire Kelvin connection across four ranges, 2 kohm, 20 kohm, 200 kohm and 2 Mohm, with accuracy of +/-0.02% of reading on the best range. Each range has its own failsafe current; the maximum failsafe current is 8 mA and open-circuit voltage is only 1.6 VDC, which keeps the device well below any initiation threshold. A built-in RS232C interface and optically isolated power are included, and the unit fits the OP-519 rack-mount tray. The 620VL is UL-913 compliant, built under ISO 9001:2015, has been in service on the U.S. Navy Vertical Launch Assembly, and is used at NASA and USAF sites. Note the lowest range starts at 2 kohm: if your devices sit below that, without a diode, the 620RK or 620VL-T is the better fit.

Key specifications
| Display | 4½ digit LED |
|---|---|
| Connection | 4-wire Kelvin |
| Resistance ranges | 2KΩ / 20KΩ / 200KΩ / 2MΩ |
| Accuracy (2KΩ range) | ±.02% of reading & ±.05% of range |
| Resolution (2KΩ range) | 0.1 Ω |
| Nominal test current (2KΩ range) | 50 µA |
| Open-circuit voltage | 1.6 VDC |
| Maximum failsafe current | 8 mA |
| Maximum input voltage | 250 VDC |
| Operating temperature | 0–50°C |
| Power | 4 rechargeable 5AH NICAD batteries |
| Dimensions / weight | 9″ × 10″ × 3″ / 4 lbs |
Features
Diode-in-series testing
Built for explosive devices that have a diode in series with the bridge-wire, so firing circuits with protective diodes can be measured without special fixtures.
Intrinsically safe by design
Every range has a failsafe current; the maximum is 8 mA and open-circuit voltage is 1.6 VDC, so the measurement cannot initiate the device.
Four accurate ranges
2 kohm to 2 Mohm in four ranges with 4-wire Kelvin connection, +/-0.02% of reading on the best range and 0.1 ohm resolution.
RS232C data interface
Built-in RS232C port and optically isolated power for data logging and automated test integration.
4-1/2 digit LED display
A large LED readout that stays legible on the shop floor and in the lab.
Military approvals and rack compatibility
UL-913 compliant, ISO 9001:2015 manufacture, in service on the U.S. Navy Vertical Launch Assembly, and compatible with the OP-519 rack-mount tray.
Typical applications

Naval weapons
Acceptance testing of igniters for naval Vertical Launching Systems (VLS)
The 620VL has been used on the U.S. Navy Vertical Launch Assembly for pre-delivery resistance acceptance of igniter assemblies fitted with series protection diodes. Test current goes as low as 0.05 uA, so the bridge-wire is measured accurately with no risk of firing the element, protecting the build quality of shipboard ordnance.
Aerospace and defense
NASA and USAF pyrotechnic safety testing
In rocket motors, ejection seats and missile fuzes that use diode-protected igniters, engineers run the 620VL for resistance surveys at assembly, storage and maintenance. Readings go straight into the quality system over RS232C, meeting the traceability requirements of ISO 9001:2015 and MIL-STD-810F programs.


Hazardous environments
Routine igniter checks on site in explosive-gas environments
With UL-913 intrinsic-safety compliance and EU ATEX approval (EEX-9B-IIC-T4), the 620VL can measure diode-protected initiators in place at mines, petrochemical plants and magazines. The devices stay inside the hazardous area, which shortens inspection downtime and removes the handling risk of moving them out.
Options and configuration
Tick the options you need. We compile the configuration into a list and carry it into the quote request form.
Standard equipment (included)
Hardware options
Downloads
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