Operating instructions

ACCEPTANCE TESTING
5-17
Audio voltmeter
Specification
Level accuracy:
±3% ±3 mV ± resolution 20 Hz to 50 kHz, AC
±1% ±50 mV ± resolution, DC
Resolution:
1 mV or 1% of reading
Test equipment
Description Minimum specification Example
LF generator 50 Hz to 50 kHz 30 mV to 5 V RMS IFR 2965
DC power supply 0 to 50 V
DVM DC measurement and AC measurement 20 Hz to
50 kHz
Solatron 7150+
LF generator
C2591
DVM
AF INPUT AF GEN
OUTPUT
VOLTMETER
INPUT
TERMINALS
UUT
Fig. 5-12 Audio voltmeter level accuracy checks
(1) Refer to Results t
able 5-19 on page 5-38. Connect the equipment as shown in Fig. 5-12,
connecting the LF generator output to the UUT AF input and via a T-piece to a DVM.
(2) Press
[HELP/SETUP], [Setup], [AF Filters], [Factory Preset], [Return], [Return], [Return].
Set the UUT to [AF TEST] press [AF Filter], [50 kHz LP] to set the Audio Input filter to
50 kHz Low-pass. Press AC/DC coupling until AC coupled is displayed.
(3) Set the DVM to measure Volts AC and the LF generator to frequency 1 kHz, level 30 mV
RMS (adjust until the DVM indicates as close to 30 mV as possible). Check that the level
indicated on the UUT voltmeter is within ±3% ±3 mV ± resolution of the level indicated on
the DVM.
(4) Repeat step 3 with LF generator levels of 200 mV, 0.4 V, 0.8 V, 2 V, 4.5 V.