VF
232.1m
0.67R
Battery State Indicator
Blinking signal gives the warning of low
battery indicating when the battery volts
drop to 6.5V.
Cursor Position
This indicates the current cursor position in
metres or feet.
Velocity Factor Indicator
Indicates the current velocity factor as either
a ratio of the speed of light (R), or as m/
µ
s
or ft/
µ
s.
Menu
The menu allows the units of the distance
and velocity factor to be changed.
To enter the menu, switch the instrument on
holding down the warble key.
To change the displayed units, press one of
the velocity factor keys. The options
available are m and Ratio, m and m/us,
ft and Ratio and ft and ft/us.
When selected, either switch the instrument
off, or press the warble key to start testing.
Cursor Left
This control moves the cursor to the left.
Range
This is a bi-directional range control. Press the left
side to decrease the gain, right side to increase.
Cursor Right
This control moves the cursor to the right.
Power
Pressing this button will turn the instrument on or
off depending on the current state.
Velocity Factor
Use this key to change the velocity factor to a
suitable value for the cable under test.
Warble
Press to select the warble functions, or to return to
TDR functions. Warble function can be used to
trace cables.
VF
+
SPECIFICATION
Except where otherwise stated, this specification applies at an
ambient temperature of 20
O
C.
General
Ranges
30m, 100m, 300m, 1000m, 3000m.
(100ft, 300ft, 1000ft, 3000ft, 10,000ft.)
Accuracy
± 1% of range ± pixel at 0.67VF
[Note:- the measurement accuracy is
for the indicated cursor position only
and is conditional on the velocity factor
being correct.]
Resolution
1% of range.
Input Protection
For connection to unenergised cable
only.
Output Pulse
5 volts peak to peak into open circuit
from 100
Ω
source. Pulse widths
determined by range and cable
impedance.
Gain
Automatic with gain and range.
Velocity Factor
Variable from 0.01 to 0.99
in steps of 0.01.
Refresh Rate
Three times a second.
Power Down
Automatic after 5 minutes
with no key press.
Warble
5V pk-pk from 100
Ω
, alternating
between 810Hz and 1110Hz.
Batteries
Six LR6 (AA) type batteries,
Manganese-alkali or nickel-cadmium
or nickel-metal-hydride cells.
Nominal Voltage
9V for Alkali or 7.2V for NiCad.
Battery Consumption
100mA nominal.
(30 hours’ continuous use.)
Safety
This instrument is to be used on
unenergised cable only.
EMC
Complies with Electromagnetic
Compatibility Specifications
(Light industrial) BS EN 61326-1,with a
minimum performance of ‘B’ for all
immunity tests.