Voltech AT3600, User Manual

Page: 47 / 56

S
AFETY
V
OLTECH
AC I
NTERFACE
U
SER
M
ANUAL
98-072
ISS
7
PAGE
47
5.3. VOCX – O
PEN
C
IRCUIT
V
OLTAGE
The accuracy is based on the chosen test conditions, and is given by:
𝐴𝐴
𝑇𝑇
= 𝐴𝐴
𝑅𝑅
+ 𝐴𝐴
𝐶𝐶
+ 𝐴𝐴
𝑉𝑉
+ 𝐴𝐴
𝐸𝐸𝑅𝑅𝐶𝐶𝐸𝐸
where:
A
T
is the total accuracy (%)
A
R
is the basic relative accuracy (%)
A
C
is the calibration accuracy (%)
A
V
is the correction for voltage level (%)
A
SRCE
is the correction for external source type (%)
The value of A
R
is from Section 5.1 Specification Summary. The other factors for this test are:
𝐴𝐴
𝐶𝐶
= 0.08% + (0.001% ∗ 𝐹𝐹
𝑀𝑀
)
𝐴𝐴
𝑉𝑉
= 0.03% + (
0.01%
𝑉𝑉
𝑀𝑀
)
𝐴𝐴
𝐸𝐸𝑅𝑅𝐶𝐶𝐸𝐸
= 0.5% ( 𝐹𝐹𝐹𝐹𝐹𝐹 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚 𝐹𝐹𝐹𝐹 𝑚𝑚𝑙𝑙𝑚𝑚𝑙𝑙 𝑠𝑠𝑚𝑚𝑠𝑠𝑠𝑠𝑚𝑚𝑠𝑠 )
𝐴𝐴
𝐸𝐸𝑅𝑅𝐶𝐶𝐸𝐸
= 0.0% ( 𝐹𝐹𝐹𝐹𝐹𝐹 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝐹𝐹𝑎𝑎 , 𝑚𝑚𝑚𝑚𝑠𝑠𝑚𝑚𝑙𝑙𝑎𝑎𝑙𝑙𝑙𝑙𝐹𝐹 𝐹𝐹𝐹𝐹 𝐴𝐴𝐴𝐴 𝐹𝐹𝑚𝑚𝑜𝑜𝑠𝑠𝑚𝑚𝑜𝑜 𝑜𝑜𝑡𝑡 )
where:
F
M
is the test frequency (Hz)
V
M
is the measured voltage (V)
During a VOCX test the AT3600/AT5600 automatically applies the test voltage to the part under test and
checks that the voltage has stabilized before recording measurements.
The time that the voltage takes to stabilize will vary with the source type used and the nature of the part
under test. In general (and especially for source types 'Programmable' and 'AT Output Transformer'), the
AT3600/AT5600 will record a measurement very quickly, (typically in less than 0.5 seconds) which is
desirable in a production test environment.
If the measurement were to be recorded after a longer period under power, slightly different readings may
be obtained due to self-heating effects in the part under test.
This effect may be noticed when comparing results taken using different source types or with slower
measurement systems.