Fluke 1742 User Manual page 63

2
 
1 PF –
 
Formula 1: 0.5 + ------------------------ - % +0.005 %
×
3 PF
 
2
 
1 PF –
 
Formula 2: 1.2 + ------------------------ - % +0.005 %
2 × PF
 
2
 
1 PF –
Formula 3:  1.2 + ------------------------ -  % +0.0075 %
2 × PF
 
2
 
1 PF –
Formula 4:  1.7 + ------------------------ -  % +0.0075 %
×
2 PF
 
2

1 PF –
 × ------------------------ -
Formula 5: 1.2 + 1.7
PF

Example:
Measurement at 120 V/16 A using an iFlex1500-12 in low range. Power Factor is 0.8
σ
Active power uncertainty :
P
2
  
1 0.8 –
σ
±
=   1.2 % + ------------------------ -  + 0.005 %
P
×
2 0.8
  
± (
The uncertainty in W is 1.575 %
σ
Apparent power uncertainty
σ
= ± ( 1.2 % + 0.005 % × S
S Range
The uncertainty in VA is ± ( 1.2 %
Reactive/non-active power uncertainty
σ
± ( × ) ± (
= 2.5 % S = 2.5 %
Q
In case of a measured voltage that is >250 V, the additional error is calculated with:
×
=
Adder 0.015 % S High Range


% +0.005 %


× ± (
P Range  = 1.575 %

× × × )
120 V 16 A 0.8 + 7.5 W
:
S
) = ± ( 1.2 % + 0.005 % × 1000 V
× 120 V × 16 A + 7.5VA ) = ± 30.54 VA
σ
:
Q
× × ) ±
120 V 16 A = 48 var
× ×
=
0.015 % 1000 V 1500 A
× × )
+ 0.005 % 1000 V 150 A =
±
= 31.7 W
× 150 A ) = ± ( 1.2 % + 7.5 VA
=
225 W/VA/var
Power Quality Logger
Electrical Specifications
± ( )
1.575 % + 7.5 W
)
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