50
Selecting the exponential averaging have been activated the combo box of time constant. You can
choose the proper time constant and this function doesn’t offer the automatic stopping with [ Stop].
Frequency weighting is used to analyze the noise with A, B, C, D, W weighting filter. A-weighting
is an ordinary weighting in noise analysis. The combo box of [Nth Octaves] has 1/1 octave, 1/3
octave and 1/6 octave.
FFT based octave analysis is dependent on the options of FFT analysis. So you have to set the
option of FFT properly. For example, if the linear averaging with 20 iterations is set, octave analysis
is calculated from linear averaged spectrum with 20.
7. Setting the option of display
Pressing the display option button
generates the window of [Fig. V-7-1]. The adjusting
frequency and magnitude axis is used in frequency analysis, spectrogram and octave analysis. The
range of frequency axis defines the start frequency and end frequency in the FFT graph. And the scale
of frequency axis is defined linear axis or logarithms axis. Frequency range is editable in linear scale,
but it is impossible in logarithms scale. The units in magnitude axis is displayed with RMS(
2
/
m s
or
Pa
) , Peak(
2
/
m s
or
Pa
), Power(
2
4
/
m
s
or
2
Pa
) and scale is displayed with linear / logarithms /
decibel scale.
For example, if you want to see the decibel of RMS value, you have to set that the unit is RMS and
the scale is dB.
There is another way for adjusting magnitude axis. If user clicks the Y-Axis by stylus pen, the
range of Y-Axis is automatically adjusted.
[Fig. V-7-1] Option Window Display
[Fig. V-7-2] Auto-scaling of Magnitude Axis
Cross marker represents the maximum peak of spectrum with frequency and magnitude after [Peak
Auto-Detecting] is turned on. And if you press any peak of FFT graph for 1second, big cross marker
appears with current frequency and magnitude instead of the value of peak auto-detecting. Pressing
the screen for a short time turned off that function. The rightmost bar graph is overall level.
Summary of Contents for SLA-PA201
Page 64: ...64 Appendix 1 The Theory for calculating RMS by ISO2631 and ISO8041 ...
Page 67: ...67 Appendix 2 Frequency Response of Filter in the Vibration Level Meter ...
Page 75: ...75 Appendix 3 Theory of WBCombined Filter and Frequency Response ISO6954 Filter ...
Page 79: ...79 Fig 2 Lowpass Filter with 100Hz Cutoff Fig 3 a v transition Frequency Response ...
Page 88: ...88 Fig 12 Error between theoretical value and measured value ...
