F-1.
General
This section of the manual contains routine
maintenance information regarding the
AMPTEC RESEARCH 620ES 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.
The AMPTEC 620ES igniter tester is a four
wire Kelvin ohmmeter.
The AMPTEC
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 “300”
is Gold Plated 4 Wire Kelvin ( or equivalent)
Clip Test Lead Set that should be used to
calibrate the AMPTEC 620ES Igniter Tester.
The 4-wire configuration is maintained up to the
point of the connection to the resistance
standard.
F-2.
Required Test Equipment
Following standard resistors are required to
calibrate the 620ES Igniter Tester .
Precision Resistors:
0.001 ohm ± 0.01% Accuracy
0.1 ohm ± 0.01% Accuracy
1.0 ohms ± 0.005% Accuracy
10 ohms ± 0.005% Accuracy
100 ohms ± 0.005% Accuracy
100 KiloOhm ± 0.005% Accuracy
Test Leads:
4-wire Kelvin Test Lead set or
(
AMPTEC
Option "300")
F-3.
Calibration Procedure
The AMPTEC
620ES should be calibrated with
fully charged batteries
( NICAD)
and should be
allowed to
warm-up
for a minimum of 15
620ES
minutes
before beginning the calibration
procedure. The calibration adjustments are
accessed by removing the screws in the feet of
the unit, then lifting off the lid to access the
main PCB trimpots. The locations of the
adjustments are shown on drawing number 620-
600 at the back of this manual.
F-3-1. Zero Offset Adjustment
(20 ohm and
higher ranges)
1.
Select the 20 ohm range. Connect the Kelvin
leads to the 0.1 ohm standard resistor.
2.
Adjust potentiometer RV2 for a display
indication of 00.10 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
(20 ohm and
higher ranges)
1.
Select the 200 ohm range. Connect the
Kelvin leads to the 100 ohm standard resistor.
2.
Adjust RV1 for a display reading of 100.00.
1.
Select the 2 ohm range. Connect the 4 wire
Kelvin leads to the 0.001 ohm standard resistor.
2.
Adjust potentiometer RV5 for a display
indication of 0.0010 Ohms .
Do not over adjust
RV5 past a 0.00 reading
. A false or negative
polarity 0.0010 display reading offset error can
be created. This calibration error (
mis-adjusted
beyond zero
) has the display appearing normal
(even though a negative 0.0010 offset has been
created ) - the display doesn't indicate a negative
sign)
F-3-4. 2 ohm range Full Scale Adjustment
1.
Select the 2 ohm range. Connect the Kelvin
F-3-3 2.0 ohm range Zero adjustment
