Fluke 52120A, User Manual

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Front-Panel Operation
Introduction
2
2-3
Introduction
The Product can be configured to operate in a stand-alone configuration or controlled by
an Electrical Power Standard like the Fluke 6100B or 6105A. The inputs of multiple
Products can be connected to one power standard. Then the current output from each
Product can be connected in parallel to a load. Each Product can be set so that each
output has a different ac phase angle.
Notes on Product Use
Accuracy
The specifications in Chapter 1 for stand-alone operation do not include the errors of the
instrument that supplies the voltage or current signal to the Product input. To get the
absolute accuracy of the current output, use the “root sum of squares” (RSS) procedure.
To calculate total accuracy:
First calculate:
√
specA
2
+ specB
2
= total specification
Multiply the total specification by the coverage factor to get the expanded accuracy at the
necessary confidence probability. The most commonly used confidence probabilities for
this type of product are shown in Table 2-1.
Table 2-1. Confidence Probabilities
Confidence Probability Coverage Factor Divisors/Multipliers
95 % 2.00
99 % 2.58
Not Stated 1.73
In this example, the 5720A has an output of 1.2 volts at 20 Hz applied to the Product. The
Product is set to the 120 A range with LCOMP off. The Product and 5720A have
confidence probability specifications of 99 %. It is not necessary to change them to
standard confidence before you calculate the specification with the RSS procedure. For
this example, the 5720A has a confidence probability of 95 % and the Product 99 %.
Table 2-2 shows how the total accuracy is calculated.
Table 2-2. Total Accuracy Calculation
Calculation Steps Expanded Standard
5720A output of 1.2 V at 20 Hz (240 ppm + 40
μ
V) 0.0273 %
Divisor to convert to standard confidence 2.00
5720a standard confidence 0.0137 %
Product output 120 Amp at 20 Hz, LCOMP off 0.0350 %
Divisor to convert to standard confidence 2.58
Product standard confidence (0.015 % + 0.020 %) 0.0136 %
Root sum of squares (RSS) 0.0192 %
Multiplier to convert to 99 % confidence 2.58
Combined accuracy at 99 % confidence 0.0497 %