Voltech AT5600, Руководство пользователя

Страница: 224 / 438

C H A P T E R 1 0 – S P E C I F I C A T I O N S
AT5600 User Manual 98-119 issue 14
Page 224
10.2.16. WATX and STRX Tests (External Source)
The measurement accuracy is based on the chosen test conditions, and is given
by:
𝐴
𝑇
= 𝐴
𝑀𝐴𝐺𝑋
+ 𝐴
𝑉𝑂𝐶𝑋
+ 𝐴
𝑃𝐹
where:
A
T
is the total accuracy (%)
A
MAGX
is the accuracy of the MAGX current measurement (%)
A
VOCX
is the accuracy of the VOCX voltage measurement (%)
A
PF
is the correction for power factor (%)
The accuracies of the MAGX and VOCX measurements are computed from the
formulae in 10.2.7 and 10.2.9.
𝐴
𝑃𝐹
= [1.0% + (0.001 % ∗ 𝐹
𝑀)
] ∗
√1 − 𝑃𝐹
2
𝑃𝐹
where:
F
M
is the test frequency (Hz)
PF is the power factor of the load
and:
𝑃𝐹 =
𝑊
𝑉𝐴
where:
W is the measured power (W)
VA is the product of MAGX and VOCX results
When performing either of these tests, the 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 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.