User Manual

Power Logger
Electrical Specifications
73
Example:
Measurement at 120 V/16 A using an iFlex1500-12 in low range. Power Factor is 0.8
Active power uncertainty 

:


=±1.2 % +
√
.

×.
 + 0.005 % × 

=±
(
1.575 % + 0.005 % × 1000 × 150 
)
=±
(
1.575 % + 7.5 
)
The uncertainty in W is ±
(
1.575 % × 120 × 16  × 0.8 + 7.5 
)
=±31.7 W
Apparent power uncertainty 

:


=±1.2 % + 0.005 % × 

=±
(
1.2 % + 0.005 % × 1000 × 150 
)
=±(1.2 % +7.5 )
The uncertainty in VA is ±
(
1.2 % × 120 × 16  + 7.5 
)
=±30.54 VA
Reactive/non-active power uncertainty 

:


=±
(
2.5 % × 
)
=±
(
2.5 % × 120 × 16 
)
=±48 
In case of a measured voltage that is >250 V, the additional error is calculated with:
=0.015 % × 
 
=0.015 % × 1000 × 1500 =225 W / VA / var