Feltest AirSpeed/2 Instruction Manual page 8

Fast or Slow key. To return to the 2-second average the instrument
must be switched off and on again.
Error indication
If the display shows E.xx when switching on or during operation, this
indicates a fault. The fault can be identified from the E-number details
under Technical Data in chapter 5.
Measurement
When it is safe to measure the air speed, the measuring head is held
against the felt, above the slit of the Uhle
box. The slit in the measuring head should
be in contact with the felt, the round hole
should be 'on top'.
By rotating the measuring head a few deg-
rees clockwise and counter clockwise one
will see that the measured air flow will vary.
There is no rule of thumb for the right
angle; it depends on felt weight and water
content, felt speed, width of the slit and the
force with which the measuring head is pressed onto the felt. Generally
spoken the position which gives the highest test results is the best.
After switching on the instrument, averages are calculated over 2
seconds (every 0,5 second a value). Pressing the Min/Max key will
return the minimum and maximum test results measured. Pressing the
Flow key will return to the current test values.
Where greater accuracy is required and the flow is rather irregular the
test time can be extended, resulting in an average over 6 seconds
(press the Fast key) or 22 seconds (press the Slow key). During the
measurement the remaining test time up to the end is indicated in
seconds. The Mean or average value of the complete measuring cycle
will be calculated when the measuring time has ended. A new meas-
urement is started by pressing the Fast or Slow key again. To return to
the 2 second average, the instrument needs to be switched off and on
again.
When the display shows BATT the battery (9 Volt) has to be replaced.
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