Megger TDR2000/2 Guide De L'utilisateur page 8

MENU definitions:
Test Rate: This sets the screen update rate to once per second or three
times per second.
Pulse Width: This option allows the user to override the default pulse
width set by the instrument for a particular measurement range and select
an alternative pulse width.
(See the Instrument Specification at the end of this user guide for full
details on the pulse options for each measurement range).
Pulse Height: Three pulse heights options exist. 3 V, 5 V and 14 V .
14 V is not available when the instrument test range is less than 400 m.
Averaging: When trying to locate cable features when a high gain is
required, any noise on the Cable Under Test (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 instrument has the
ability to average two or more results. Any noise will be reduced. Options
of 1x, 2x, 3x or 4x over-sampling can be set in the MENU.
Zero (ns): 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 20 ns, however to zero non standard test leads
proceed as below:
1 Set the instrument measurement range to 50 metres.
2 Enter the MENU (key 11)
3 Set the Distance Units to ns.
4 Set the ZERO (ns) to 0.
8
5 Press the MENU key again to exit the configuration menu.
6 Select display mode L1
7 Measure the time (in ns) to the ends of the test leads. To
identify this point on the trace open circuit and close circuit the
end of the test leads and note the distance.
8 Enter the MENU again (key 11).
9 Set the ZERO (ns) to the measured time.
All measured distances will now be shown relative to the end of the test
leads.
Power down: Allows the user to set the automatic power-down to 5, 10
or 15 minutes after the last key press.
Display: Switches off the backlight after a pre-defined period, 1, 2 or 5
minutes.
Language: This allows the user to select the language required, from
English (default) to French, German, Spanish, Italian. Other languages can
be downloaded from the Tracemaster CD supplied with the instrument.
VF Unit: The velocity factor (VF) can be displayed as a ratio of pulse
speed to the speed of light, or as a distance per microsecond in either feet
or metres. Refer to the Velocity Factor section for more details.
Distance Unit: The distance to cursor measurement can be displayed in
metres [m], feet [ft] or in time, eg [ns].
50/60Hz Filter: If ON, a power supply frequency filter is switched on.