HP 400F, Руководство по эксплуатации и обслуживанию, Страница: 13 / 54

Model 400F /FL Section ID
SECTION III
OPERATIN G
3-1. INTRODUCTION.
3-2. This section contains instructions and information
necessary for the operation of the 400F/FL AC Volt­
meters. Included is identification of controls� indi­
cators and connectors. turn on proceduresiand oper­
ating instructions.
3-3. CONTROLS, INDICATORS AND
CONNECTORS.
3-4. Each control� indicator, and connector on the
400F/FL is identified and described in Figure 3-1.
3-5. METER MECHANICAL ZERO ADJUSTMENT
(400F ONLY).
3-6. The mechanical zero adjustment is located in
the center of the instrument front panel. If the meter
pointer does not indicate zero after the instrument has
been off at least one minute. mechanically zero the
meter. following the steps outlined below.
a. Turn instrument power off. and allow at least
one minute for meter pointer to stabilize.
b. Rotate zero adjustment screw clockwise until
pointer is left of zero and moving upscale.
c. Continue rotating screw clockwise until
pointer is at zero. Stop when pointer is exactly
on zero. Iipointer overshoots, repeat step b.
d. When pointer is exactly over zero, rotate
adjustment screw slightly counterclockwise to
relieve tension on pointer suspension.
If
pointer moves to the left. repeat whole pro­
cedure, but make counterclockwise rotation
less.
3-7. TURN ON PROCEDURES.
a.
If line voltage is used, ensure that the 115-230
vac switch (located on the rear panel) is in the
correct position. Turn the line ON toggle
switch to the ON position. The LINE lamp
will glow, indicating that line power is
applied.
b. If batteries are used, connect two 35 to 55
volt batteries as shown in Figure 3-2. The
line ON switch is not in the circuit when bat­
teries are used, therefore an external DPST
switch should be used to provide a means for
disconnecting the batteries when the instru­
ment is not in use.
01795-2
INSTRUCTION S
BATTERY VOLTAGE
35-55
35-55
+
_ _ _
-11
+
_11
+
92 91
(35-55V)
(35-55V)
Figure 3-2. External Battery Connection
3-8.
AC VOLTAGE MEASUREMENTS.
Since the 400F/FL is average re­
sponding and rms calibrated, any
distortion will affect the accuracy of
the measurement. Table 3-1 shows
the errors caused by distortions.
Table 3-1. Effect of Distortion on Average Respond­
ing Meter
%
ERROR
(
'
Fundamental)
HARMONIC
%
DISTORTION
MAlL
MAlL
NEGATIVE
Any even 0.1 0.000
0.5 0.001
1.0 0.005
2.0 0.020
Third 0.1 0.033 0.033
0.5 0.168 0.167
1.0 0.338 0.328
2.0
0.687 0.667
Fifth 0.1 0.020 0.020
0.5
O.
101 0.099
1.0 0.205 0.195
2.0 0.420 0.380
*Depends on phase relationship between harmonic
and fundamental.
3-1