CHAPTER F - 620VN CALIBRATION AND MAINTENANCE
F-1.
General
This section of the manual contains routine main-
tenance information regarding the AMPTEC
RESEARCH 620VN Igniter Tester. Calibration
should be performed on a regular basis to ensure
continued instrument accuracy or following a
main PCB electronic component
repair/replacement. The recommended calibration
interval is 1 year.
All AMPTEC 620 series Igniter Testers are four
wire Kelvin compensated ohmmeters.
The 620VN
Igniter Tester must be calibrated using four wire
Kelvin connections to the resistance standard
in
order to eliminate lead resistance and contact
resistance errors. The Option “290” has 48” long
coax test cabling terminated with twin single
alligator clip jacks will not work properly for
calibrating the 620VN.
Note:
Only for 620 versions with a 2 Ohm range:
Option "300" is a 48" long Gold Plated Kelvin
Clip Lead set optionally supplied as part of the
AMPTEC 620 accessories is recommended for the
actual calibration of 620 Igniter Testers versions
fitted with a low 2.0 Ohm range.
F-2.
Required Test Equipment
Following standard resistors are required to cali-
brate the 620VN Igniter Tester.
Precision Resistance Standards:
.01 ohm ± 0.01% or better accuracy
10 ohm ± 0.005% or better accuracy
100 ohm ± 0.005% or better accuracy
1.0 Kohm ± 0.005% or better accuracy
10.0 Kohm ± 0.005% or better accuracy
100 Kohm ± 0.005% or better accuracy
1.0 Mohm ± 0.1% or better accuracy
Test Leads:
AMPTEC "Option 300" Kelvin Clip Lead Set
F-3.
Calibration Procedure
The 620VN Igniter Tester must be calibrated with
a fully charged battery pack and should be
allowed to
warm-up
for a minimum of
15
minutes
before beginning the procedure. The
calibration adjustments are accessed by removing
the screws in the feet on the bottom of the unit,
then lifting off the lid. The locations of the
adjustments are shown on drawing number
620VN -600 at the back of this manual.
F-3-1. Zero Offset Adjustment
1.
Select the 20
ohm range. Connect the Kelvin
clips to the 0.010 ohm standard resistor.
2.
Adjust potentiometer RV2 for a display indica-
tion of 0.010 Ohms .
Do not over adjust RV2 past
a 0.00 reading
. A false or negative polarity 0.010
display reading offset error can be created. This
calibration error has the display appearing normal
(even though a negative 0.010 offset has been
created ) - the display doesn't indicate a negative
sign).
F-3-2. Full Scale Adjustment
1.
Select the 2000 ohm range. Connect the
Kelvin clips to the 1.0 Kohm standard resistor.
2.
Adjust RV1 for a display reading of 1000.0
ohms.
3.
Check the 20 Ohm range with
a 10 Ohm
resistance standard (std).
Check the 200 Ohm
range with
a 100 Ohm
resistance standard (std).
Check the 20 KOhm range with 10 KOhm
resistance
std.
Check the 200 Kohm with a 100
Kohm resistance std. Check the 2.0 MegOhm
range with the 1.0 MegOhm resistance std. All
ranges should be within the specifications out-
lined in Chapter B.
There are no individual
adjustments necessary for the 20ohm, 200 ohm,
20K, 200K and 2.0 MegOhm ranges.
Contact
AMPTEC’s customer service department if
further technical support is necessary.
page 20
