Fluke 415B - Page 27

41
5B
NOTE!
To
obtain best output
stability
from the Model
41
5B, the HIGH VOLTAGE
switch
should be
set to
STDBY
/RESET and
the POWER switch
left
ON. This will
maintain an even
distribution
of
heat within
the unit and
prevent
the need
for
recurrent warmups.
For highest
stability
appli-
cations, the OUTPUT
VOLTAGE
dials should
be
set to the
desired voltage
and
the HIGH
VOLTAGE switch
left ON.
2-12.
APPLICATIONS
2-13. Calibration
of Meters
2-14. The Model
415B may
be used for direct
calibra-
tion of
dc
instruments to an
accuracy of
0.
25%
or 100
millivolts
(whichever
is greater)
at 3100 cardinal
points,
1
volt apart, from
0 to 3099
volts. The vernier
dial
provides an additional
1.
2 volts of
range for calibration
between cardinal
points. Proceed
as follows:
a. Set the POLARITY switch to
the desired
polarity.
b.
Connect the
instrument being calibrated
firmly to
the power
supply. Check the external
circuit for
conflicts in grounding
before applying power to
the
load.
c. Set the
HIGH
VOLTAGE switch
to ON. The
STDBY/
RESET lamp
will
extinguish and the
HIGH VOLTAGE
ON lamp
will
illuminate.
d.
Set the first four
0
TT
TP
TT
T
VOLTAGE
dia
1
^
to t
K,;>
desired cardinal point.
Use the last dial if a cali-
bration point between
the one volt cardinal points
is desired.
e.
To remove the output voltage from the output
con-
nector, set
the HIGH VOLTAGE
switch
to STDBY/
RESET.
2-15.
When
used
with
a John Fluke differential volt-
meter
and voltage divider, the
415B
is capable of cali-
brating
dc
instruments from
0
to
3100
volts
with
an
accuracy
of 0.
01%
to 0.
06%
with 5 millivolts resolution.
For
calibration of instruments from 0 to 1100 volts,
proceed
as follows:
a.
Set the
POLARITY switch to the desired polarity.
b.
Connect
the
instrument
being
calibrated
securely
to
the power
supply.
Check the
external circuit
for
conflicts
in grounding
before applying
power
to
the load.
c.
Connect a
John Fluke
differential
voltmeter to the
instrument
being
calibrated.
d.
Set the differential
voltmeter
to
measure the voltage
desired at the calibration
point.
e.
Set
the
HIGH
VOLTAGE switch
to
ON. The STDBY/
RESET
lamp will extinguish and
the
HIGH
VOLTAGE
ON lamp
will illuminate.
f.
Null the differential
voltmeter
by
adjusting
the
OUT-
PUT VOLTAGE
dials.
The
accuracy
of the
voltage
measured is
from 0.
01%
to
0.
05%, depending
on
the
accuracy of the
differential
voltmeter
used.
g.
Set the
HIGH VOLTAGE
switch
to
STDBY/RESET.
h.
Repeat steps d.
through
g.
for as
many
calibration
points as
desired.
2-16.
For calibration
of instruments
from
1100
volts
to
3100
volts,
px'oceed as follows:
a.
Set the
POLARITY switch
to the
desired
polarity.
b. Connect
the instrument
being
calibrated
firmly
to
the power
supply.
Check
the external
circuit
for
conflicts in
grounding
before applying
power
to
the
load.
c.
Connect a John Fluke
Model
80N-5 Voltage
Divider
to the instrument
being
calibrated and
connect
the
differential
voltmeter to
the voltage
divider
output
terminals.
d. Set
the differential
voltmeter to
measure
the volt-
age
at the desired
calibration point,
considering
the
ten-to-one
division ratio of
the
voltage
divider.
e.
Set the HIGH
VOLTAGE switch to
ON.
The
STDBY/
RESET
lamp will
extinguish and
the
HIGH
VOLTAGE
ON
lamp will
illuminate.
f. Null the
differential
voltmeter
by .adjusting
the OUT-
PUT VOLTAGE
dials. The
accuracy
of the voltage
i o f r*rv»y* a_p CiP.Of
r
^ ^
~
the accuracy
of the differential
voltmeter and
volt-
age
divider
used.
g.
Set the HIGH
VOLTAGE switch
to
STDBY/RESET.
h. Repeat
steps d. through
g.
for
as many calibration
points as
desired.
2-17. Operation
with a Reference Divider
2-18.
When the
output of the Model
415B
is
compared
to a
standard
cell by way of
a reference divider, the
Model 415B can be set to
provide voltages of an accuracy
greater than the inherent
accuracy
of the
instrument.
When used with the
Model 750A
Reference
Divider and
the Model
845AB
Voltmeter/Null Detector, the Model
415B
can
provide
voltages
0.
1,
0.
5,
1.
0, 5,
10,
100,
500,
1000,
and 1100
volts
which have an accuracy of
10 to
20
ppm, and are traceable to the National Bureau
of
Standards. Connect
the
equipment as shown
in
Figure
2-3
and
proceed
as follows:
a.
Set the Model
415B
HIGH VOLTAGE
switch
to
STDBY/RESET and the POWER switch
to
ON.
b.
Set the Model 750A
STANDARD
CELL
dials
to
the
voltage value
of
the
standard
cell
being used.
c.
Set the Model 750A
INPUT
VOLTAGE
switch to
1100
volts
or the
highest voltage desired.