D-1.
General Operation
D-2. Front Panel Features and Operation
Range Switches
A diagram and description of the front panel
controls, connection instructions, and the theory
behind resistance measurement is discussed in
this section.
Power Switch
When the front panel power switch is placed in
the OFF/CHARGE position, all power is
removed from the ohmmeter measurement pins
of the J1 connector (see E-6), and the battery
pack is connected to the charging circuit. When
the switch is placed in the ON position, the
battery pack is disconnected from the charging
circuit. In addition the keyed connector on the
640N front panel only allows either connecting
a) the battery charger or connecting b) the test
lead set but not both. The possibility of any AC
line power/voltage interference between the
device under test and AC Line Power
. The operator
can not be concerned if the battery charging
adapter is plugged into the 640N as it is then
impossible to make any resistance
measurements.
The AMPTEC 640N input range is selected by
depressing the desired range switch (protected
with the given silicone rubber boot for water
resistance) on the front panel. The pushbutton
for the (20 Ohm ) lowest resistance range is just
below the display on the left, (see item 20 of the
640N Front Panel Diagram.). When a given
range is selected an indicator LED informs the
user. Also note that a resistance range must be
selected after powering up the 640N in order to
place it in an operational mode, that is when first
turned on a range must first be selected.
This section of the manual contains
complete operating instructions for the
AMPTEC 640N Igniter Tester.
is
therefore completely eliminated
Calibration Access Screws
Function Test Section
Around the perimeter of the 640N front panel
you will note there are 10 screws (philips head
type) that are used for calibration access. These
screws are meant to remain intact and should
only be removed by authorized personnel (i.e.
Calibration Lab staff).
The Function Test Section of the 640N contains
an analog 10 mA fullscale milliammeter and a
variety of test resistors.
With one test lead (i.e. red banana ) plugged
into the meter panel jack and the other test lead
(i.e. black banana lead) plugged into the
common panel jack, the milliammeter will
display the actual test current coming from the
640N Igniter Tester, when the test leads are
connected and the 640N is in operation mode.
The span of the DC milliammeter is 0 to 10
milliamperes fullscale. If the test leads are
connected backwards to the 640N DC
milliammeter, the milliammeter will not
measure any 640N output, as the current
polarity is reversed. For the 640N with the 20
Ohm range selected, using the onboard
milliammeter, a test current level less than 5
mA is normal. The 640N failsafe current
circuitry limits the 640N such that
of 8 mA or higher.
Keep in mind the
proper resistance range should be selected in
order to measure a selected test resistor. You
can’t measure a 1000 ohm resistor on the 20
ohm range of the 640N. With one test lead (i.e.
red banana lead ) plugged into the selected test
resistor panel jack and the other test lead (i.e.
black banana lead) plugged into the common
panel jack, the 640N Igniter Tester should
display a resistance value close to the labeled
value of the resistor. The 0.1 ohm resistor is
commonly used to test the bottom or
one should
never see a current level
The test resistors for the Function Test Section
may also be used to verify general 640N
operation and functionality.
low end
CHAPTER D - OPERATION, FUNCTIONAL
SELF- TEST AND USE
Summary of Contents for 640N
Page 19: ......
