Amptec Research 620ES Manual
OPERATION/MAINTENANCE MANUAL
09JUNE2011 REV. E
PHONE (512) 858-4045; 800-350-5105
website http://www.amptec.com
FAX (512) 3858-4340; TOLL FREE IN USA
2.0 (I.9999) Ohms Fullscale with
0.1 milliohm (100 µ ) Resolution
620ES Safety Igniter Tester
Option "110" Test Lead Pouch
TABLE OF CONTENTS
_______________________________________________________________
CHAPTER A: RECEIVING AND INITIAL INSPECTION
A-1 Introduction to the AMPTEC 620ES series
A-2 Unpacking and Inspection
A-3 AC Adaptor/ Battery Charger- Power Requirements
A-4 Setup and Use
CHAPTER B: 620ES FAILSAFE OHMMETER SPECIFICATIONS
Table B-2. Specifications
CHAPTER C: REPLACEMENT, OPTIONAL AND ACCESSORY ITEMS
C-1 Available Accessories and Options
C-2 Test Lead Sets
CHAPTER D: OPERATION, FUNCTION AND USE
D-1 General
D-2 Front Panel
D-3 4-Wire Resistance Measurement
D-4 Connections
D-5 Failsafe Operation
D-6 Battery Monitoring Circuitry
Figure D-1 Error sources in Resistance Measurements
CHAPTER E: GENERAL OPERATION AND DESIGN
E-1 General
E-2 Troubleshooting
E-3 Circuit Descriptions
E-4 Analog-to-Digital Converter
E-5 Ohms-to-DC Converter
E-6 Failsafe Design
E-7 Ultra-Safe Power Supply Scheme
Figure E-1. Model 620ES Block Diagram
Figure E-1B Analog-to-Digital Converter Timing Diagram
Figure E-2 Analog Section of IC1 and IC2
Figure E-3. Constant Current Source Diagram (Simplified)
Figure E-4. LED Display Pin Functions
CHAPTER F: ROUTINE MAINTENANCE
F-1 General
F-2 Required Test Equipment
F-3 Calibration Procedure
F-4 Battery Replacement Instructions
A-1. Introduction to the AMPTEC 620ES
The AMPTEC 630, 640 and now the 620 Series
Igniter Testers/Failsafe Ohmmeters are
becoming the standard in the Safety Igniter
Circuit Test industry, and are designed to
provide extremely safe and reliable resistance
testing of explosive or volatile devices. Safety
Approvals from various Safety Boards include,
the U.S. Air Force ( 620A-4) for generic use on
Non-Nuclear munitions and the US NAVAL
ORDNANCE CENTER (620AN and other
versions pending). Some of the devices the
620ES Igniter Tester may be used on include:
fuses, squibs, igniters, explosive bolts, rocket
motor squibs, automobile air-bag initiators and
many others.
The AMPTEC 620ES is a 4-wire failsafe digital
ohmmeter which has been designed to reliably
use very low test currents for its resistance
measurement. Failsafe Output Circuitry
proprietary to AMPTEC RESEARCH ensures
that test current levels do not exceed the
specified "failsafe current" even in a worst-case
component failure situation. The failsafe feature
is tested in every instrument before shipment.
The newer 620 series represent the latest in
ultra-safe Igniter Tester measurements. The
620ES uses the same main printed circuit board
(PCB) as all of the AMPTEC 620A Igniter
Testers. The 620ES has many features which
make it useful in a variety of applications.
Please check the last chapter of this manual for
addendums that may apply to the 620ES.
Should the rechargeable batteries reach a low
charge level a negative sign will apear on the
display. The 620ES has a battery monitoring
circuit that indicates it is time to plug in the
battery charger.
A-2. Receiving, Unpacking, and Initial
Inspection
Should the AMPTEC shipping box appear
damaged upon arrival, request that the carrier's
agent (i.e. UPS) be present when the unit is
unpacked. If the 620ES appears damaged, the
carrier's agent should authorize repairs before
the unit is returned to the factory. Even if the
instrument appears undamaged, it may have
suffered internal damage in transit that may not
be evident until the unit is operated or tested to
verify conformance with its specifications.
If the unit fails to operate or fails to meet the
performance specifications of Section B, notify
the carrier's agent and the nearest AMPTEC
Sales Office. Retain the shipping carton for the
carrier's inspection. DO NOT return
equipment to AMPTEC RESEARCH or any
of its sales offices without first obtaining an
(RMA) Return Material Authorization number.
We need to know who to contact and how to
contact (i.e. phone number and FAX number) in
order to properly coordinate the return of the
repaired AMPTEC product.
By calling AMPTEC RESEARCH first, prior
to just returning the 620ES, we can often
troubleshoot (based on the symptoms you
describe) and identify the problem over the
phone (i.e battery loose in the battery holder).
We may possibly be able to fix the problem over
the phone and prevent you from having to return
the unit to AMPTEC for repair.
R M A
SECTION A - RECEIVING AND INITIAL INSPECTION
A-3. AC/DC Battery Charger - Power
Requirements
The AMPTEC 620ES is powered by an internal
rechargeable heavy-duty nickel-cadmium battery
pack (4 ea D cell - 5.0 AHr). Replacement batteries
may be purchased, contact the sale department at
AMPTEC RESEARCH.
The battery charger is an external AC/DC converter
that plugs into a standard 115VAC receptacle. The
AC powered battery charger provides 6VDC @
250mA for charging the AMPTEC 620. The
AMPTEC 620ES is designed so it is impossible to
be powered (in operating - measurement mode)
directly from the AC line battery charger. As an
additional note, the 620ES main power switch must
also be in the “Off/Charging” mode in order for the
connected battery charger to recharge the 620ES’s
batteries.
For customers using 220VAC 50 HZ AC line power
for running the battery charger, please inform
AMPTEC’s sales department at the time of your
order and the appropriate adaptor will be included
with the 620ES Failsafe Ohmmeter shipment for an
additional fee.
A fully charged battery pack typically powers
the 620ES for approximately 6 ~ 8 hours before
requiring a recharge. AMPTEC installs a quality
set of 4 each Heavy Duty (5000 mAHr) Ni-Cad
batteries. The 620ES will also operate on a 4000
mAhr D cell Ni-Cads with a shortened operating
time between charges. Recharge time is
typically twice the “Power On” time. An
“Overnight” charge
usually restores the 620ES to a “Fully Charged”
ready to use state.
The main “Power” switch has two separate
modes. The “ON” position supplies internal
battery isolated power to operate the 620ES
when they are charged. If you turn on the
620ES, and the display does not come on, it
may indicate the batteries need charging. The
“OFF/ CHARGING” power switch position is
for use when the batteries need charging or the
620ES is not in use. As mentioned earlier of
course the AC/DC Battery Charger must be
plugged into the 620ES’s rear panel charging
jack/ connector to facilitate charging the
batteries.
Although the batteries are fully charged prior to
shipment, it may be desirable to refresh the
charge for 24 hours before use. As a rule of
thumb, the 620ES requires twice as much time
to fully recharge as the amount of discharge
time. For example, if the instrument was used
continuously for 2 hours, the AC adapter must
be connected for 4 hours in order to fully restore
the charge. If you need a replacement AC/DC
Battery Charger for the 620, contact the
AMPTEC customer service department and
request an option “620DC” Battery Charger.
Located on left hand portion on the 620ES
display is the “Low Battery” indicator box.
Check for no “Low Battery” indication. If the
LED display shows a negative (-) or minus sign
in the indicator box the unit’s batteries are low
and need charging. The absence of the negative
sign in the battery indicator box indicates the
batteries are acceptably charged.
Fuse
(2 Amp-fast blo)
620ES
When the 620ES is first turned on, the unit
draws more internal power to heat up the unit’s
ovenized zener voltage reference. If the “Low
Battery” Indicator only comes on for a few (i.e
10 to 15 seconds) seconds when the 620ES is
first turned on then goes out, the battery levels
are starting to indicate the charge level is getting
low.
A-4. Setup and Use
The AMPTEC 620ES Igniter Tester may be
setup to operate within minute(s) of power "turn
on" (unless your in an extremely cold
temperature - allow more time for warm-up - 15
minutes). A quick check for no sign of the "low
battery indicator" and test lead integrity check
and it should be ready to use.
Once the AMPTEC 620ES has had it’s batteries
charged for 12 to 24 hours it is ready for use.
The 620ES consumes little power and generates
virtually no heat. Consequently, it may be used
in any area where the environment does not
exceed the specifications of Table B-2.
Avoid exposing the 620ES to extremes of
temperature which will affect accuracy and
shorten battery life-span.
CHAPTER B - 620ES EXPLOSIVE SAFETY
IGNITER TESTER - SPECIFICATIONS
______________________________________________________________
Actual fail-safe currents vary with each instrument and may be ±20% from the typical value.
Table B-2. Specifications
Accuracy: (for 1 year @25°C ± 10°C)
2.0 ohm range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±0.02% of reading ±0.05% of range
20 ohm through 200 ohm ranges . . . . . . . . . . . . . . . . ±0.02% of reading ±0.02% of range
200 Kohm range . . . . . . . . . . . . . . . . . . . . . . . . . . . ±0.05% of reading ±0.05% of range
Temperature Range
Operating 0°C to 50°C
Storage -10°C to 70°C
Temperature Coefficient
20 ohm through 20K ohm ranges ±0.002% per °C (from 0°C-15EC and 35°C-50°C)
Instrument Display . . (20,000 count) 4½ digit Super Bright Light Emitting Diodes (LED)
Over-Range Indication . . . . . . . . . . . . . . . . ( select next higher range) Display flashes
Measurement Update Rate . . . . . Approximately 300ms
Voltage Protection - Maximum Input . . . . 250VDC or AC without damage
peak
Open Circuit Current Source Compliance Voltage . . . . . clamped at ~1.6 volts
Power . . . . (4 "D" 5.0 AHr Heavy Duty) 1.2V rechargeable nickel-cadmium batteries
or OP 247 Continuous Isolated Operating Power
AC/DC Battery Charger (Option DC) provides 6VDC at 250 mA nominal
Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.5" (24cm) W x 11" (27cm) D x 3"(8cm) H
Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 lbs net; 15 lbs shipping
620ES Resistance Range/Resolution 620ES Nominal Test Current/Failsafe Current Levels
C-1. Available Accessories and Options
Listed below are the options available for use with
the AMPTEC 620A Series FailSafe Ohmmeters.
Option 620DC: Battery Charger
Option "DC" is an AC/DC converter that converts
115VAC line voltage to 6VDC at 300mA. One
charger is provided as a standard accessory with
every 620A. A 220 VAC 50 Hz powered Battery
Charger adapter is also available.
Replacement Batteries
The rechargeable Nicad batteries installed in the
620A should provide years of trouble-free operation.
Replacement, however, will eventually be necessary.
The 620A uses four 1.2V cells (5.7 AHr
recommended) installed in a reusable battery box.
When ordering replacement batteries, please specify
AMPTEC Stock #0E-10117, quantity four (4).
Option 100: Carrying Case
Option "100" is a hardshell (impact resistant plastic)
shock absorbing foam lined meter and accessory
carrying case for the 620A Ohmmeter with extra
room for test leads, battery charger, Kelvin Clip Test
Leads, Connector Adapters, single pointed probes
and operator manual etc.
Option RACK: Rack Mount Adapter
Option "620RACK" includes an adapter tray that
allows any AMPTEC 620 series tester to be flush
panel mount installed in a standard 19"
equipment rack.
C-2. Test Lead Sets and Probes
Option “290" Alligator Clip Lead Set
Option "290" is the recommended general
purpose Alligator Clip test lead set (red and
black) for models not having a 2.0 Ohm range
(due to a small resistance “offset” at the tips -
OK for 20 Ohm and higher range units ) . Option
“290" is supplied as a standard item with all
620A-4 (USAF version) ohmmeters as part of
the accessory package. Option “290" is a 48"
long cable set with dual banana plugs at one end.
The other end is terminated with an alligator clip
( red and black) . Some “Squib Resistance” test
panel jacks have a plastic exterior with a
conductive socket center. These alligator clips
will measure (2 wire method) properly with
either upper or lower jaw connected to the
conductive socket center of plastic test panel
jacks. Kelvin Clips see Option “300” (using the 4
wire method) may have difficulty only if both
jaws (both upper and lower) do not make
electrical contact with the conductive “resistance
under test” center.
See next page for Kelvin Clips and other
accessories.
SECTION C OPTIONAL ITEMS AND
ACCESSORIES
Option 401: Handheld Single Probe Leads
Option "401" is a 620 series compatible handheld
probe (one black probe & one red probe ) lead set
terminated in single points. The OP401 handheld
probes allow for easy access to connector socket
wiring (i.e. drone parachute squib sockets), recessed
surfaces, and parts (i.e. flares) that alligator clip
leads simply would not work well with.
Option “500” Optically Isolated Analog Output
Option “600” Optically Isolated Binary Coded
Decimal (BCD) Data Output
New Options and Custom Leads Available
Contact the sales department at AMPTEC
RESEARCH (phone 1-800-350-5105) if you have
need for GPIB, a special probe, adapter, lead set, or
custom option not listed in this manual. AMPTEC’S
experienced application engineers have helped sup-
ply many customers with special igniter tester acces-
sory requirements.
This rear panel mounted isolated analog DC Voltage
output signal is directly proportional to the 620
tester's ohm display measurement. (i.e. 1.2345 VDC
for 12.345 ohms). It is used to track 620 tester mea-
surements for datalogging purposes with an external
device (i.e chart recorder, system DMM with GPIB).
Isolation protection is rated @2000 volts peak to
insure any instrument connected to "Option 500" has
virtually no impact on the 620 series tester's safety.
For applications requiring data output the 620 series
is available with “BCD”output. The measured resis-
tance readings are output via a rear panel “BCD” talk
only interface. A High- Go- Low BCD Dual Limit
Comparator is presently under development and will
be available Summer of 2001..
Option 300: 4-Wire Gold Plated Kelvin Lead Set
Option "300" is a general purpose Gold Plated
Kelvin four wire Leads for all AMPTEC 620 series
Testers. Gold plated kelvin clips provide a low
thermal EMF connection (minimizes the thermo-
couple effect) with most connections. The Option
“300” is the recommended test lead set for any
AMPTEC Igniter Testers with a 2.0 Ohm range
(i.e models 630ES and 620ES). The 4 wire Kelvin
connection is important when measuring less than
1.0 ohm, and also automatically eliminates test
lead length offset and test lead contact resistance
errors. Option “300” is a shielded 48" lead set
terminated in ½" opening gold plated Kelvin clips.
The option "300" can clip easily to wires, pins, and
medium size (up to ½" diameter conductors). The
dual banana plug ends connect directly to the 620
tester's front panel input terminals. (see Option
"320" for replacement Kelvin clip ends only)
Option 305: Banana-to-Banana Cable
Option "305" is a 48" shielded cable terminated in
dual banana plugs at both ends.
Option 320: Kelvin Clips
Option "320" are the gold plated kelvin clips used
on the Option "300" cable set . These clips may be
used when making custom cables or when repairing
Option "300".
Option 360: Heavy-Duty Clips
Option "360" are Gold-plated jumper cable (large
jaws) type clips used on the Option "350" cable.
They are still Kelvin Clips because the insulated
upper and lower jaw (jumper cable appearance)
integrity is maintained. These may be used when
making custom heavy duty cables that open to 1
1/2 " wide (i.e bolt heads)..
Functional Test Section - The optional 620ES Functional Test Box provides added measurement integrity
using a milliammeter and test resistors to cross check the overall 620ES operation whenever desired. The
test resistors are for cross checking 620ES basic operation and should not be used for calibration purposes.
Simpsontm DC Milliammeter Range - 0-10 mA fullscale, Accuracy ±3%
FTSR1 01-23572 0.1W 1.0 % Resistor, Tc- 25ppm/°C, ¼ W
FTSR2 01-23575 10.0W < 0.1% Resistor, Tc- 10ppm/°C , ¼ W
FTSR3 01-23577 10.0 KW <0.1% Resistor, Tc- 10ppm/°C, ¼ W
FTSR4 01-23583 100 KW <0.1% Resistor,Tc- 10ppm/°C, ¼ W
FTSR5 01-23587 10.0 MW <1.0% Resistor, Tc- 20ppm/°C, ¼ W
FTSR6 01-23589 19.0 MW <1.0% Resistor, Tc- 50ppm/°C ,¼ W
MILLAMPERES
2
4
6
8
10
100.0 KOHM
10.0 KOHM
10.0 OHM 10.0 MOHM
620ES
Functional
Test
Box
19.0 MOHM
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