Amptec Research 620A-4 User Manual

T.O 33D5-14-52-1
OPERATION / MAINTENANCE MANUAL
AMPTEC RESEARCH MODEL 620A-4
FAILSAFE DIGITAL OHMMETER/
IGNITER CIRCUIT TESTER
NSN 6625-01-460-1499AQ
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Published under authority of the Secretary of the Air Force
18 JULY 2000
ORIGINAL
AMPTEC RESEARCH IS AN ISO 9001:2015 CERTIFIED QUALITY MANAGEMENT COMPANY

Amptec Research 620A-4 Specifications

General

Brand	Amptec Research
Model	620A-4
Category	Measuring Instruments
Language	English

Summary

SECTION A: RECEIVING AND INITIAL INSPECTION

A-1. Introduction to the AMPTEC 620A-4

Introduces the AMPTEC 620A-4, its applications, and industry standards.

A-2. Receiving, Unpacking, and Initial Inspection

Guides on handling the unit upon arrival, unpacking, and initial inspection for damage.

A-3. AC/DC Battery Charger - Power Requirements

Specifies power requirements for the AC/DC battery charger and its operation.

A-4. Setup and Use

Provides instructions for setting up and using the AMPTEC 620A-4.

A-5. Serial Number, Revision and Safety Board Approvals

Details serial number, revision information, and safety board approvals for the 620A-4.

SECTION B - 620A 4 TESTER SPECIFICATIONS

SECTION C - OPTIONAL ITEMS AND ACCESSORIES

C-1. Available Accessories and Options

Lists various optional accessories and upgrades available for the AMPTEC 620A series.

C-2. Test Lead Sets and Probes

Details different test lead sets and probes compatible with the 620A-4.

SECTION D - OPERATION AND USE

D-1. General Operation

Provides general operating instructions for the AMPTEC 620A4 Explosive Safety Igniter Tester.

D-2. Front Panel Features and Operation

Describes the front panel controls, power switch, and range selection.

D-3. Rear Panel

Details the rear panel layout, including the fuseholder and charging jack.

D-4. 4-Wire Resistance Measurement

Explains the principle and benefits of 4-wire Kelvin resistance measurement.

D-5. Connections

Details how to make connections to the front panel terminals using the 4-wire configuration.

D-6. Failsafe Operation

Describes the failsafe design and operation of the AMPTEC 620A Series Igniter Tester/Ohmmeter.

D-7. Battery Monitoring Circuitry

Explains the battery monitoring circuitry and low battery indicator function.

Replacing the AMPTEC 620A-4 Handles

Rotating the AMPTEC 620A Instrument Case and Handle Position

SECTION E - GENERAL OPERATION AND DESIGN

E-1. General

Provides an overview of the AMPTEC RESEARCH 620A-4R Igniter Tester's general operation and design.

E-2. Troubleshooting

Guides on troubleshooting common malfunctions and identifying problems with the 620A Tester.

E-2-1. Localizing the Problem

Provides guidelines for localizing electronic problems by parameter before component identification.

E-2-2. Component Replacement

Outlines procedures and precautions for replacing faulty components in the 620A Tester.

E-3. Circuit Descriptions

Explains the equivalent circuit of the analog section in different phases of operation.

E-4. Analog to Digital Conversion

Details the Analog-to-Digital conversion process using specific integrated circuits.

E-4-1. Reference Voltage

Explains the precision reference voltage required for the A/D conversion.

E-4-2. LED Display

Describes the LED display output format and its operation.

E-5. Ohms-To-DC Converter

Explains how the ohms-to-DC converter generates a constant current for measurement.

E-5-1. Constant Current Source

Details the components and operation of the constant current source circuit.

E-5-2 Constant Current Circuit Operation

Describes the operation of the constant current circuit under various conditions.

E-6. Failsafe Design

Explains the failsafe design of the AMPTEC 620A Tester to prevent excessive voltage or current.

E-7. Ultra-Safe Power Supply Scheme

Details the ultra-safe power supply scheme, including battery and DC/DC converter operations.

E-8. Relay Board General Operation

Explains the general operation of the relay board, responsible for range selection.

SECTION F: ROUTINE MAINTENANCE

F-1. General

Contains routine maintenance information for the AMPTEC RESEARCH Model 620A Fail Safe Ohmmeters.

F-2. Required Test Equipment

Lists the standard resistors required for calibrating the AMPTEC 620A-4.

F-3. Calibration Procedure

Details the procedure for calibrating the 620A, including adjustments and checks.

F-3-1. Zero Offset Adjustment

Provides steps for performing the zero offset adjustment during calibration.

F-3-2. Full Scale Adjustment

Provides steps for performing the full scale adjustment during calibration.

F-4. Battery Replacement Instructions

Provides step-by-step instructions for replacing the rechargeable Nicad batteries in the 620A.