Specifications

Regular maintenance with an accurate,
dependable DMM ensures early detec-
tion of harmonics in the AC supply. One of
the quickest ways to detect and gauge the
percentage of distortion due to harmonics
is to measure the harmonic ratio of the
incoming AC voltage.
Harmonic ratio
Measuring circuit
RMS-calculating
converter calculates
heating value
Multiplies rectifi ed
average by 1.1
Correct
Correct
Correct
Correct
10% high
Up to 50% low
Response to
sine wave
Response to
square wave
Response to
distorted wave
V
rms –
V
avg
V
rms
V
rms
V
avg
x 100%
Switch counter for detection of glitches on switch and relay systems
Careful maintenance of the switches
and relays used in facilities and
machinery helps ensure that they’re
operating as expected in their OPEN or
CLOSED settings. You can check their
performance with just one button using
the U1240 Series’ switch counter function.
This function detects intermittent OPEN or
CLOSED occurrences across relay/switch
contacts in the reversed setting. The total
count indicates the extent of relay/switch
faults and determines if further trouble-
shooting is necessary.
The U1240 Series offers a fast one-button
check with its harmonic ratio function.
The ratio percentage helps you decide if
further analysis of the power source is
necessary with an oscilloscope or a
spectrum analyzer.
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