Sencore FE149 - Page 5

OHMS ADJ: The OHMS ADJ is the same as that found оп most meters. Prior to
measuring resistance, the FE149 leads are shorted together and the OHMS ADJ is
rotated for a full scale deflection(zero ohms) as readon the ohms scale of the meter.
FUNCTION SWITCH: The FUNCTION SWITCH is a push button switch used to select
the desired function for the measurements to be performed by the FE149. Simply
push inthe desiredfunction, plusor minus DC volts, AC volts, Ohms, BATT check,
plus or minus DC current or AC current, a total of 8 functions.
RANGE SWITCH: The RANGE SWITCH is a push button switch to select the desired
range ofcurrent, voltage or resistance to be measured with the FE149. There are
a total of 8 different ranges available on the FE149.
OPERATING THE ЕЕ149
Тһе Sencore FE149 Senior Field Effect Meter is extremely easyto operate. Simply
depress the desired function button on the FUNCTION switch and depress the de-
sired range button on the RANGE switch, connect theleads, and read the results on
meter. Here is a brief description of how each test is performed with the FE149.
ADING DC VOLTS: To read DC volts on the FE149, depress either the minus
DC or plus DC button on the FUNCTION switch. Depress the desired range button
for the voltage to be measured from .5 volts to 1500 volts on the RANGE switch. If
the voltage to be measured is unknown, start with one of the higher ranges to see
how much voltage is present and depress the range button that will give the desired
meter deflection. When measuring DC voltages in RF-IF circuits, a 100K resistor
at the endof the probe lead will reduce the capacity loading effects and not upset the
circuits for the most accurate readings.
The
DC
voltage
is
read
on
the
two
black
scales
just
above
the
mirror
on
the
meter.
The
top
DC
scale
is
from
zero
to
.
5
volts
and
each
mark
is
equal
to
.
01
volts.
Тһе
bottom
scale
is
zero
to
1.
5
volts
and
each
mark
is
equal
to
.
02
volts.
The
zero
to
5
scale
is
used
for
the
.
5,
5,
50,
and
500
volt
ranges
and
the
zero
to
1.5
scale
is
used
for
the
1.5,
15,
150,
and
1500
volt
ranges.
In
use,
the
meter
indication
is
multiplied
by
1,
10,
100,
or
1000
depending
upon
the
range.
For
example,
if
the
15
volt
RANGE
button
is
depressed
and
the
meter
reads
.
68
volts,
the
actual
voltage
is . 68 times 10 or 6.8 volts DC.
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L— vorracse —J
.5У 1.5V 5V 15V 50У 150У 500У 1500У
DC RANGES WITH 39421 HI V PROBE——SKV 15КУ 50KV
READING DC VOLTS ZERO CENTER SCALE: The zero center scales are used to
read plus or minus voltages without the necessity of changing polarity with the leads
or Function switch. То use the zero center scales, depress the plus DC voltage
function button and adjust the ZERO ADJ control until the meter pointer reads at the
ro mark inthe center of the scale. This isthe scale directly below the mirror оп
3 meter. This gives ranges of plus or minus zero to . 25 volts (top scale) and plus
minus zero to .75 volts (bottom scale), times 10, 100, or 1000 depending upon
the range button that is depressed. If the meter swings up scale or to the right, it
is a positive voltage. If the meter swings down scale or to the left it is a negative
voltage. This unique feature allows you to determine the polarity as well as the
amplitude of a DC voltage and is very handy in solid state work.
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