Megger TDR2000 Manual De Instrucciones página 12

Pulse Widths: This option allows the user to override the
default pulse width set by the instrument for a
particular range and select an alternative
pulse width available within the range. (See
the Specification section for the table of pulse
widths and the section under Instrument
Features for more details.)
Distance Units: This option allows the user to select whether
the cursor distance will be displayed in
metres, feet or nano-seconds.
Averaging: When trying to locate cable features when a
high gain is required, any noise on the C.U.T
will be amplified as well as the reflected
pulse. This noise may make accurate location
of the cable feature more difficult. To
overcome this, the TDR2000 has the ability to
have averaging where the cable is over-
sampled and any random noise should be
greatly reduced. This option allows this to be
set at 1x, 2x, 3x or 4x over-sampling.
Note: A high over-sample rate can reduce
the
battery lifetime.
VF Display: The velocity factor can be displayed as a
ratio
of pulse speed to the speed of light or as a
distance per microsecond. This option selects
the display type. Please refer to the
12
Instrument Feature section for more details.
Zero Point: This setting enables the zero point of the
instrument to be set at the end of the test
leads, so the test lead length is automatically
deducted from any distance calculation. The
nominal zero point setting for the standard
test leads is 20ns, however to zero non
standard test leads please take the following
steps:
1. From the Config Menu - Options set the Range to a
range suitable for the test leads.
2. Set the Distance Units to nS.
3. From the Config Menu - Setup set the Zero Point to 0.
4. Press the MODE key to exit the Config menu and
display a trace.
5. Measure the distance (in nS) to the ends of the test
leads, to identify this open circuit and close circuit the
lead end.
6. In the Config Menu - Setup set the Zero Point to this
measured time.
All measured distances will now be shown relative to the end of
the test leads.
Power down: This allows the user to set the power down to
5, 10 or 15 minutes after the last key press.