Amptec Research 620A 4R, Operation And Maintenance Manual

IGNITER TESTER

Figure D1 - Igniter Tester Kelvin Block Diagram

*

* contact resistance

*

 4.8 VDC BA

TTER

Y

HIGH IMPEDANCE 

   VOL

TMETER

COMPLIANCE
VOLTAGE
LIMITED
CONSTANT
CURRENT
SOURCE

IGNITER

LEAD RESISTANCE

LEAD RESISTANCE

P

O

O

L    

T

N

E

R

R

U

C

DC to DC ISOLA

T

OR

DC to DC ISOLA

T

OR

from the AC line powered battery charger. Also 
the main power switch of the 620A-4R must be 
in the “OFF” position, in order to switch the 
unit into charging mode..

6. Low Battery Indicator

 - Negative sign at 

the front of the digital display indicates “low 
battery level” time to recharge.

7. Fuse Access

 required for general operation - 

2 ampere slow blow type. 

8. Battery Charger

Storage Area

  -Press 

Battery Charger’s Velcro

tm

  against Velcro

tm

 on 

the surface to attached/store the charger , cord 
and its mating connector.  The 620 must also 
have the main power switch in the “off” 
(charging) position while charging the unit’s 
batteries.   

9. Water Resistant O-ring

 seal(s) in lid and 

under the edge of the front plate. 

10. Tight Squeeze Flip Latch Area

 -  pro-vides 

a water resistant seal when closed. While 
pressing down with palm on corner of case, flip 
latch up to open.

11. Resistance Ranges

  20ohms, 200ohms, 2.0 

Kohms and 20.0 Kohms silicone rubber switch 
boots provide water resistance.

12.  Power On or Off/Charging Switch

13.  Beveled Display Hood with Super Bright 
LED s 

(five times brighter than normal LEDs). 

D-4.    Fuseholder and Charging System

Fuseholder

The fuseholder is mounted on the front panel 
and contains a 2 amp in-line fuse (see item #7 
of the 620A-4R Diagram.).  The fuse protects  
internal batteries from excessive charging 
currents.  Replace blown fuses with the same 
type and rating only!

The Charging System

The slimline AC to DC battery charger with  
connector is a  connector that mates

with the battery jack labeled “Battery 
Charger”).  The connection is made on the front 
panel (see item # 5 of the  620 Series Igniter 
Tester Front Panel Diagram shown earlier). The 
power switch (item #12) must also be in the 
“Off/Charging” mode while the battery charger 
is connected to recharge the batteries. 

The measurement test leads (dual banana style) 
connect to the 

V

hi, 

V

low and other lead 

connects to the Current (

I

Hi) and Current (

I

lo) 

low 620A-4R panel banana jacks.  The charging 
requirements supplied to the internal battery 
pack are internally stepped down from the 
9VDC @1.1A supplied by the charger. The 
correct charging voltage is supplied by the 
adapter included with the instrument.  

Additional AC/DC Battery Chargers are 
available as Option "620A-4RDC". An 
overnight charge (16 hours) will provide about 
an 6  to 8  hours continuous powered up life for 
the 620A 4R. The 620A 4R has an internal 
ovenized voltage reference the draws a 
considerable amount of battery power when 
first turned on. If you know you will be using 
the 620A 4R again in 10 to 15 minutes, you 
actually 

conserve battery

 power 

by not turning 

it off

. 

D-5.   4-Wire Resistance Measurement

The four-terminal configuration of the 620A 4R 
eliminates errors normally caused by in series 
test lead resistance and contact resistances.  In 
many applications the contact resistance and 
can exceed the value of the test resistance by 
several orders of magnitude.  The 620A 4R 
overcomes