The AMPTEC 620UK Explosive Safety Ohmmeter () is a portable digital ohmmeter for "Intrinsi-

cally Safe" resistance testing in explosive and volatile atmo-spheres ( aircraft bond measurements), explosive devices (e.g.squibs, igniters, flares ) and munitions. The AMPTEC 620UKOhmmeter complies with the EU ATEX Directive and the Intrin-sic Safety standard Eex-ib-IIc-T4. EMC tested in accordancewith British Defence Standard 59-41 Radiated Emissions andSusceptibility

. British DEF STD 66-31 (Environ Heat, Cold,Altitude, Humidity and Atmospheric Stress tests), DEF STD 07-85 and 05-34 . The AMPTEC 620UK Ohmme-ter provides a reliable and intrinsically safe means of measuringelectrical resistance of rocket motor squibs, warhead squibs,explosive bridge wire and/on a variety of devices.

eatur resistance ranges metal case with a sepa-rate battery compartment, provides a safe and easy method ofmeasuring resistance in explosive and volatile atmospheres.

NSN 6625-99-833-7949 EEX

and.

compliant as well

The AMPTEC620UK f es seven ,

and

USA MIL STD 810 compliant ( ExplosiveGases to +50°C)

The AMPTEC RESEARCH 620UK Explosive Safety Ohmmetercomes with its own conductive (anti-static) carrying case. Thereis also an external ground lug on the outside of the case that canbe connected to the AMPTEC 620UK Ohmmeter’s chassis/caseground jack the entire time the meter is inside the carrying case.The AMPTEC 620UK Ohmmeter can easily make resistancemeasurements while still in the carrying case (shoulder strapequipped). The AMPTEC 620UK Ohmmeter case top, bottom,sides, front and rear panels are made of metal (aviationaluminum) that provides a complete Faraday Cage. All sides ofthe AMPTEC 620UK ohmmeter case are connected to the unit’sfront panel chassis ground jack to facilitate a single “earthy”connection point.

AMPTEC 620UK Explosive Safety OhmmeterIntrinsically Safe - Explosive and Volatile Atmospheres

AMPTEC 620UK Explosive Safety Ohmmeter

Conductive Case with External Chassis Ground

NSN 6625-99-833-7949

UK Ministry of DefenseApproval as EEX Compliant

Precision Ten Turn Zero Offset Adjustment

4-Wire Kelvin version eliminates in-series offsets

The unit's precision ten turn zero adjustment potentiometer canalso be “resistance offset” optimized for use with the 48” stan-dard test lead set ( ).see close-up 620UK photo on next page Theprecision zeroing capability allows the user to compensate forapprox. 1 ohm of offset (on the 2 ohm range) associated with the2-wire in-series test lead wiring resistance. For larger "in-series"resistance offsets see 4-Wire Kelvin version discussion above.

Optional 4-Wire Kelvin ConnectorMil Spec Water and Dust Resistant

The AMPTEC 620UK - (v4) is theversion with "Mil Spec" weather-proof connector with

cap. It provides a secure & popular"Test Lead" connection and a chassis ground pin. The 4-WireKelvin version " " test leads offset resistance errors &contact resistance errors that can't be compensated for with the 2wire NATO front panel .

optional

4 Wire-Kelvin resistance

Auto Nulls

4 Wire Kelvinresistance

Standard 3 pattern type 104 test connector

A= IB= VC= VD= I

HighHighLow

Low

Pins ( Optional 4 Wire Kelvin)E=F=G=H=

unused

Chassis Groundunused

xfx xfx xfxxfx xfx

xfx

xfxxfx

xfx xfxxfxxfx xfx

xfx

xfx

xfx

xfx

A 16 page copy of the MIL STD 810,Method 511 Rev F Explosive &Volatile Atmosphere Test at +50°C(www.amptec.com/tech.htm )

The US NAVAL ORDNANCESafety Board Approved on ESSMEvolved Sea Sparrow Missile squibs(www.amptec.com/tech.htm)

The UK Ministry of Defense (M.O.D.)has evaluated & approved theAMPTEC 620UK Safety Ohmmeteras a replacement Safety Ohmmeter foruse in Explosive and VolatileEnvironments.

" inregards to MOD requirements for anExplosive Safety Ohmmeter.

As a result of thisassessment the UK MOD foundAMPTEC 620UK Ohmmeter to be"fully compliant in all respects

II2G

shown with the 2 wire NATO Standard 3 pattern type 104 front panel test lead connector

AMPTEC 620UK Explosive Safety OhmmeterIntrinsically Safe - Explosive and Volatile Atmospheres

620UK Resistance Range/Resolution

Nominal Test Current/Fail-Safe Current

5mA8mA

5mA8mA

0.5mA1.5mA

50µA150µA

5µA15µA

0.5µA1.5µA

50nA15nA

Accuracy:

Temperature Range -

Temperature Coefficient

Instrument Display

Low Battery Indication

Over-Range Indication

Measurement Update RateVoltage Protection - Maximum Input

Open Circuit Current Source Compliance Voltage

PowerDimensionsWeightCalibration Access

(for 1 year @25°C ± 10°C)

Operating . . . -20°C to 40°C,Storage . . . . . . -10°C to 70°C

2.0 - 20 K ranges - ±0.005% per °C (from 0°C-15°C and35°C-50°C), 200 K range - ±0.01%/°C (from 0°C-15°C and35°C-50°C)2.0 M range - ±0.02% per °C (from 0°C-15°C and 35°C-50°C)

. . (20,000 counts) 4½ digit Liquid CrystalDisplay (LCD) with a back light for viewing the 620UK displayin dim ambient, also has , K , M display annunciators.

. .The 620UK LCD Displays shows“ ”

. . . “ ” in the bottom of

620UK LCD display. . . Approx. 3 readings per second

. . . . 250VDC or ACwithout damage

. Diodeclamped at <1.4 volts

. . . . Battery Pack (4 ea "AA") 1.5V Alkaline batteries. . . . . . . . . . . . . . . . . . . . . . 7.0" W x 8 " D x 2.5" H

. . . . . . . . . . . . . . . . . . . . . . . . 6 lbs net; 8 lbs shipping. . Optional tamper resistant security screws

&

peak

SPECIFICATIONS

The AMPTEC 620UK Ohmmeter comes with your choice of Option"620UK-290" Alligator Clip Test Lead Set or the Option "620UK-401Single Pointed Handheld Probes.

The optional 4 Wire KelvinVersion (620UK v4) also offers a complete set of Kelvin compensatedtest leads and probes.

Probes allow testing of recessedsocket/connector wiring (squib wires) and flat surfaces (aircraft bonds)which are difficult to test using alligator clip test leads. The AlligatorClip Test Leads open up to 1/2" wide to facilitate connection to posts ,pins & wires. All test lead sets are 48" long.

Low Ohm Range – Accuracy and Resolution

Alligator Clips or Handheld Probes includedOption 620UK-290 Alligator Clips Option 620UK-401 Probes

620UK Explosive Safety Ohmmeter . . . . . . .

Option “620UK-290” 48” Alligator Clip Test Lead SetOption “ ” Handheld Probe Lead SetCustom Versions

620UK-401contact AMPTEC RESEARCH Sales Dept

Option “620UK-v4” 4-Wire Kelvin Compensated Version

Order Information

*AMPTEC RESEARCH accepts VISA/MASTERCARD

The AMPTEC 620UK Explosive Safety Ohmmeter has the following

fullscale ranges – 2.0 , 20 , 200 , 2.0 K , 20 K , 200 K and

2.0 M . The AMPTEC 620UK's 2.0 fullscale range provides a two-

wire resistance measurement from 0.0000 to 1.9999 . The 2.0

range also offers a low (1/10) 0.1 m resolution. The 2.0 M rangeprovides a relatively high resistance range for a variety of applicationsincluding determining “ ” (>2M ) status or “ ” ofordnance related wiring that should be connected to the explosivedevice.

open circuit isolationnot

Many other brands of 4 ½ digit safety ohmmeters2.0 while most squibs and EEDs (Electronic Explosive

Devices) are typically around 1 ohm of resistance. Competitive 20.0

range ohmmeters force the user to measure a 1.0 squib on its 20.0

range (which is only 5% of the fullscale 20.0 range). The AMPTEC

620UK easily measures a 1.0 explosive element with

1/10 (0.1 m milliohm resolution.Competitive ohmmeters often have range/accuracy problems with tighttolerance squibs like the (ESSM) Evolved Sea Sparrow Missile’s 1.1Ohm squib that has a 0.01 tolerance, not a problem for the AMPTEC620UK ohmmeter.

lack a lowohm range

±0.02% ofreading basic accuracy and

Close-up Photo of the AMPTEC 620UK Ranges

Phone +01 (512) 858- 4045 FAX +01 (512) 858-4340 www.amptec.com10900 Research Blvd. PMB-1, Ste# 160-C Austin, TX USA 78759 email info@amptec.com