AEA Technology 20TDR, Основное руководство

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8
Function Keys
General - All the function keys activate and de-active with one press. When active the green
LED will light. Some function keys can not be operating simultaneously and will automatically de-
activate other function keys when selected.
Range Key – When active, this key uses the ◄► arrow keys to control the display
ranges. Available ranges are:
Feet
Meters
10 2
20 5
50 10
100 20
200 50
500 100
1,000 200
2,000 500
5,000 1,000
10,000 2,000
20,000 5,000
Zoom Key – When active, this key will zoom on Cursor 1 or Cursor 2. If both cursors
are on-screen, Zoom will center on the last CRSR key pressed (the active Cursor) . When Zoom
is active use the left/right arrow keys to control the zoom span. Pressing the
◄ key will reduce
the range either side of the cursor until minimum range is reached, pressing the ► key will
expand the range either side of the cursor until original range setting is reached. To disable the
Zoom function, press the Zoom key again. The LED will extinguish and the Measurement Screen
will return to the full range originally selected.
Z Scale Key – When active, this key permits control of the Z (impedance) scale on the
left side of the plot. Use the
▲▼
keys to increase or decrease the impedance scale as required.
When the impedance is reduced the TDR will keep the selected cable’s impedance centered in
the display. Example: For a 75 Ohm coax cable if the impedance is reduced to 20 Ohms the
display scale will read 65 Ohms to 85 Ohms.
Cursor 1 & Cursor 2 Keys – These keys control the use of the cursors, one or both at
the same time as follows: