Hioki 3181-01, Инструкция по эксплуатации

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8
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Chapter 3 Principle of Operation
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3.3 Integrated Watt Value
The DC voltage Ei(2 V f.s.) is proportional to the power
measured by the power meter. The V-F converter
converts Ei into a pulse train, the pulses are counted by
the counter and the result is displayed as the watthour
value. (V-F conversion rate
α = 27.7....(Hz/V))
For example, if 100 [W] is the power measured in the low
range (200 [W] f.s.), the voltage Ei input to the V-F
converter is given by the following formula.
Ei = 2 [V](f.s.)
×
100 [W] /200 [W]= 1 [V]
The time-unit switch on the 3181-01 front panel is also
the integrator RANGE switch.
If integration is
performed at Wh:Lo (TIME:MIN) for one hour, the
resulting integration value N is calculated thus:
N = α [Hz/V] × Ei [V] × T [s]
= 27.7.... [Hz/V] × 1 [V] × 3600 [s]
= 100000
By interlocking ranges and setting the decimal point at
the fourth digit from the right, it is possible to directly
display watthour values of up to 100.000 Wh. If
integration is performed for one hour with Wh:Hi
(TIME:HOUR) set, after the divide-into-100 circuit, the
following value is obtained:
N = 27.7.... [Hz/V] × 1 [V] × 3600 [s] × 1/100
= 1000
If the decimal point is set at the second digit from the
right in this case, the value 100.0 Wh is displayed. As
the above discussion shows, the maximum display value
of the integrator can be changed by different
combinations of time units and ranges (table on the next
page).