22
e.
Turn on the power in the test circuit. Read the output voltage on the appropri-
ate AC voltage scale. For the 0-2.5V range, read the value directly on the
scale marked 2.5V AC. For the 10V, 25V, 50V, or 250V ranges, use the red
scale marked AC and read the black figures immediately above the scale.
4.8
Decibel Measurement (-20 To +50 dB)
Some industries measure in terms of voltage or current ratios (decibels) based
on a specific reference level. The dB scale on the 260-8P serves this purpose and
is calibrated to a reference level (zero dB) or 0.001 watt into 600 ohms. The scale
calibration of -20 to +10 dB is for the 0-2.5V range (zero dB = 0.775V). Higher
ranges may be used by adding an appropriate dB value to the reading in accor-
dance with the chart below.
a.
Review the safety precautions in paragraph 4.1.
b.
Refer to Figure 4-11 for switch settings and jack connections.
c.
Use operating instructions for AC VOLTAGE MEASUREMENT,
0-2.5/10/25/50/250V RANGES (paragraph 4.6.1).
Do not use the 500V or 1000V ranges for decibel readings.
d.
Read decibels on the bottom scale marked dB. For the 10/25/50/250V ranges,
add the appropriate factor from the following chart:
+10
+8
+6
+4
+2
0
-2
-4
-6
-8
-10
10Hz
100Hz
1KHz
10KHz
100KHz
1MHz
FREQUENCY
2.5 VAC RANGE
10VAC RANGE
25/50 VAC RANGE
250 VAC RANGE
OUTPUT RANGES
Figure 4-9. Frequency Response
Output Ranges
500 MA.
2.5 V.
10 V.
1V.
25 V.
50 A.
AMPS.
250 V.
500 V.
I000 V.
OUTPUT
350 VDC
MAX.
COMMON
-
A.C. VOLTS
ONLY
A.C
.
A.C
.
2.5
V.A
.C
.
260
ALL TERMINALS 1 V MAX
Figure 4-10. Jacks and Switch
Positions for Output Measurements
E
G
N
A
R
E
G
A
T
L
O
E
V
G
N
A
R
B
G
d
N
I
D
A
E
R
V
5
.
2
-
0
0
1
+
o
t
0
2
y
-
lt
c
e
ri
d
d
a
e
r
V
0
1
-
2
0
2
+
o
t
8
g
-
n
i
d
a
e
r
o
t
B
d
2
1
+
d
d
a
V
5
2
-
0
0
3
o
t
g
0
n
i
d
a
e
r
o
t
B
d
0
2
+
d
d
a
V
0
5
-
6
0
3
+
o
t
6
g
+
n
i
d
a
e
r
o
t
B
d
6
2
d
d
a
V
0
5
2
-
0
0
5
+
o
t
0
2
g
+
n
i
d
a
e
r
o
t
B
d
0
4
d
d
a
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