Version 5
page 25
Signal Power Setting
The Signal Power settings control the display of the measured signal in a rainbow-
shaped color scheme. Parameters include the Threshold (Display Reference Value),
Image Range, and Image Average. The Signal Power visually shows the amount of
pressure produced in the direction of measurement on the camera, in the selected
mode/band-pass frequency. The signal power displayed on the screen can show both
the size and distribution of the source. It is dependent on the Threshold (Display
Reference Value).
The signal power is calculated at 25 frames per second and will be visible on the screen at a resolution of 640 x
480.
Threshold (Display Reference Value)
The Signal Power that appears on the screen depends on the Threshold setting. The source you are trying to
identify must be greater than or equal to the Threshold before the signal appears on the screen. For accurate
measurements, it is recommended that you set the Threshold before measurements, depending on your
measurement environment. The Threshold value can range from a minimum of 0 dB to a maximum of 120 dB.
a.
The Threshold setting is set as the minimum value of the source you want to measure.
b.
Only source levels above the Threshold setting are displayed on the screen. Values below the
Threshold setting are ignored.
Image Range
The Image Range sets the width of the Signal Power displayed. The minimum (Blue) and maximum (Red) values
can range between a minimum of 0 to a maximum of 10 dB. The higher the value, the greater the width of the
Signal Power.
The Image Range varies with the peak (maximum value). As the
sound pressure changes, the minimum value changes with the
maximum value depending on the width of the Image Range.
Raising the Threshold affects the Signal Power displayed on the
screen regardless of the set values of the Image Range. For example,
if the minimum value for the Image Range is less than the Threshold,
as shown in the graph on the left, then the Threshold is set to the
minimum value and displayed on the screen.
