Amptec Research 620A 4R, Operation And Maintenance Manual

CHAPTER  B  - 620A 4R  TESTER  SPECIFICATIONS

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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)

20 ohms  through 2.0 KOhm ranges . . . . . . . . . . . . . . . . ±0.02% of reading ±0.02% of range
20 Kohms range . . . . . . . . . . . . . . . . . . . . . . . . . . .  ±0.02% of reading ±0.02% of range

Temperature Range

Operating

0°C to 50°C

Storage

-10°C to 70°C

Temperature Coefficient

20 ohms through 20 Kohms 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) 620A 4R 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" 5.7AHr Heavy Duty) 1.2V rechargeable nickel-cadmium batteries

AC/DC Battery Charger (Option 630DC) 

provides  6 VDC at ~ 0.5 amperes nominal

Dimensions

 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.5" (34.3cm) W x 12" (30.5cm) D x 6"(15.2cm) H

Water Resistance

 . . . . . . . . . . . . . To a  3 foot depth underwater - case closed with purge valve shut 

Weight

 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 lbs  net; 15 lbs shipping

SECTION C  - REPLACEMENT,  OPTIONAL AND ACCESSORY ITEMS

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C-1.  Available Accessories and Options

This preliminary manual does not list all possible accessories that AMPTEC RESEARCH is willing to provide as a support items for the 620A 4R Failsafe 
Ohmmeter. Contact the sales department at AMPTEC if you have a request for an item that is not described here. Listed below are the options available for use 
with the AMPTEC 620A 4R Igniter Tester/FailSafe Ohmmeter.

Option 630DC:  Battery Charger

Option "630DC" is an AC/DC converter that converts 115VAC line voltage to 9VDC at 1.1A.  One charger is provided as a standard accessory with every 620A 
4R Ohmmeter.

Replacement Batteries

The rechargeable NICAD batteries installed in the 620A 4R should provide years of trouble-free operation.  Replacement, however, will eventually be necessary.  
The 620A 4R  uses four 1.2V cells (5.7 AHr recommended) installed in a reusable battery box.  The batteries are held in place by a metal  retaining plate.  When 
ordering replacement batteries, please specify AMPTEC Stock #0E-10117, quantity four (4).

C-2. Test Lead Sets

Option 630-305: Two Single Banana Cable

Option "630-305" is a 48" long replacement cable set normally supplied as part of the U.S. NAVY 620A 4R 
Ohmmeter package. The Option “630-305 has twin single banana plugs (meter and common) terminated 
with the 620A 4R style keyed connector. One banana plug is red (Voltage high and Current High) and one 
banana plug lead end is black (Voltage low and Current low) . The 4-wire configuration is maintained up to 
the point of the banana plug,  eliminating most cable resistance effects.

You may also contact the sales department at AMPTEC RESEARCH if you have need for a special probe, 
adapter, lead set or custom option not listed in this manual.  

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620A 4R RESISTANCE RANGE/DISPLAY RESOLUTION TABLE