UNI-T UTS3000B/A Series User Manual page 61

Avg|Hold Number: Set the average time of trace. User can change the average time by using the
numeric key, rotary knob, direction key or touch the panel menu. Multiple averaging can reduce the
influence of noise or other random signals, thus highlight the stable signal characteristics in the signal.
The higher the average time, the smoother the trace.
Avg Type:
1. Log-Pwr averaging is to average the logarithmic amplitude values (in dB) of the signal envelope
measured within a signal collection unit; the average detection type will change to video detection.
For random noise, logarithmic averaging = power averaging - 2.5 dB = voltage averaging - 1.45.
Therefore, it reduces the displayed level of the noise (not the true level of the noise) and it is suitable
for observing low-energy narrowband signals, especially those close to the noise.
2. Power averaging is to average the power of the signal (the square of the amplitude); the average
detection type will change to RMS (power) detection. Power averaging is true power for noise. Power
averaging is most suitable for measuring the real-time power of complex signals.
3. Voltage averaging is to average the voltage values of the signal envelope measured in a signal
collection unit; the average detection type will changed to voltage detection. The voltage averaging is
still a linear display, which is suitable for observing the rise and fall of AM signals or pulse modulated
signals (e.g., radar, TDMA transmitter).
Display Line（On/Off）: Set the display line level to change the display position. The display line is a
reference horizontal line with an amplitude value equal to the set value, and the corresponding amplitude
unit is the same as the Y-axis unit. User can change the display line level by using the numeric key,
rotary knob, direction key or touch the panel menu.
Note
The display line is a reference horizontal line with an amplitude value equal to the set value, and the
corresponding amplitude unit is the same as the Y-axis unit.
If the display line is outside the visible range, it is displayed at the top or bottom of the grid and indicated
by direction.
Limits: Set the parameter of limit. Press [Default] key to turn off the limit value measurement function,
but the limit value data is retained.
1. Select: select the current limit line, 4 limits can be selected, the default limit is 1.
2. Limit （ On/Off）: Turn on/off the limit value line display. When the limit line is opened, the measurement
interface displays the limit line, and the corresponding trace line will test according to the current limit
line. Each limit line is shown in a different color.
3. Test Trace: set the trace for the current limit line test. The default trace is 1.
4. Margin（On/Off）: Turn on/off margin display. When the margin is opened, the margin line is displayed
on the measurement interface. When it off, the margin is invalid.
5. Type（Upper/Lower）: Select the type of the current limit line as Upper or Lower. If the trace amplitude
is greater than the upper limit amplitude or smaller than the lower limit amplitude, then the test is
failed.
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