Description Of Functions - METREL MD 9270 Manual De Instrucciones

MD 9270 Leakage Clamp TRMS Meter with Power Function Description Of Functions

3. Description Of Functions

Measuring mA, A and V
The following sections show the functions available in the current (mA and A) and volt-
age (V) measurement mode (positions of the rotary switch in mA, A and V). To select
the desired function you need to press the FUNC key repeatedly until this is selected.
For current measurements (mA and A), it is recommended to disconnect the test leads
(see "Warning" section).
Efficient value measurement function
In this function, we can see the measurement of the efficient value of the current or of
the voltage together with the THD (total harmonic distortion rate). The THD is a
relationship between the frequency components of the signal with the essential
component (at 50 or 60Hz) expressed in percentage. A high THD value indicates high
distortion of the measured signal whilst a 0%THD indicates that the measured signal
wavelength is a perfect sinusoid. In this way data retention is possible as well as the
register of maximum and minimum values using the
Intelligent loss analysis (mA function only)
The ammeter clamp includes an algorithm that allows determining the cause for the
current loss. This mode is only enabled when we measure current in the mA scale and
we select the efficient value measurement. In the efficient value measurement function,
one or two icons will be shown on the screen informing of the possible reason for the
loss.
Harmonic analysis function
This clamp has the function of measuring the harmonic components of a certain magni-
tude, showing the efficient value of said harmonic on the screen at the same time as the
harmonic number When talking about a harmonic we are in fact referring to the multiple
of the network essential frequency we are working with If, for example, we measure the
3rd harmonic with a 50 Hz network frequency, we would be measuring the 150 Hz
components of the magnitude (current or voltage).
This icon indicates that the loss is possibly due to a defect in the
equipment insulation.
These two icons indicate that the loss may be partially due to
defects in the insulation and partially to the accumulation of non-
lineal loads.
This icon indicates that a loss is possibly due to a high
accumulation of non-lineal loads.
key.
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