WY Series User
’
s Manual
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©
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23
Chapter 7 Verification and Calibration
7.1 Verification conditions
①
Ambient temperature: 23
±
℃
2
;
℃
②
Relative humidity: 55%
±
20%;
③
Power supply: 220V
±
5V;
④
Frequency: 50Hz
±
2Hz;
⑤
No mechanical vibration and electromagnetic to interfere with the test
results;
⑥
Half an hour of preheating.
7.2 The required equipment
l
Standard Digital Multimeter: Can realize DC measurement, and the accuracy
should be better than 0.1%.
l
Standard impedance: Used for the output current measurement. 0.1
Ω
standard
impedance should be adopted if the output current is less than 2.5A while a 0.01
Ω
standard impedance is recommended if the output current is over 2.5A.
l
Load: the load impedance should make the instrument export the maximum rated
power. For example: the load impedance of WY305, whose maximum rated
power is 30V/5A, is 6
Ω
.
7.3 Verification Items
7.3.1
Basic Error of output voltage
Wiring as shown in Figure 7.1, the instrument works in the constant voltage state,
"CV" indicator lights up, put the selection switch for sampling at "inside". Adjust the
output voltage to the tested points within the limited range of DC power supply. The
basic error
of output voltage
can be calculated by equation (1):
Δ
= B
XV
－
B
NV
---------------------------
（１）
