BRUEL & KJAER 2305 - Page 40

drive speed now corresponds to the small figures marked
around the PAPER SPEED knob ).
2. Set the PAPER DRIVE toggle switch to "Start" commen-
cing the paper to run, this will continue until the built-in
automatic single chart stop switch declutches the drive
mechanism (one chart length or less).
3. Lower the pen by the cam A.
4. Start the recording by pressing down the SINGLE CHART-
CONT. RECORD
pushbutton for a short while and then
release it.
A
chart of 250 mm length wiII now be recorded, whereafter
the recording wiII automatically stop. (However, it is possible
at any time to stop the recording by setting the PAPER
DRIVE toggle switch to "Stop").
(b) Continuous Reeordlng:
The following method is recommended:
1. Set the SYNCHRONIZING GEAR LEVER X in its in posi-
lion (released). (The actual paper drive speed corresponds
to the large figures marked around the PAPER SPEED
knob).
2. Lower the pen by the cam A.
3. Start and stop the recording by means of the PAPER
DRIVE,
START-STOP toggle switch .
It is also possible to obtain continuous recording with the
1: 10 synchronizing gear engaged (Lever X in its outer posi-
tion). The operator should then follow the instructions out-
lined under (a), "Single Chart Recording", except that to
start the recording it is necessary to press the SINGLE
CHART-CONT. RECORD pushbutton and turn it clockwise to
its position "Cont. Record" . Recording will now automatically
take place until the pushbutton is released and the PAPER
DRIVE,
START-STOP toggle switch is set to "Stop".
NOTE: Whenever the PAPER DRIVE, START-STOP toggle
switch is in the "Stop" position the paper drive is
completely controlled bYlhe SINGLE CHART-C:ONT
RECORD
pushbutton .
IV.
Reading of Absolute Values from the Reeordlng.
The absolute values can be read from the recording by using the
formula:-
The value in dB on the re.:ordin{l
+ the number of dB indicated by INPUT ATTENUATOR, re o 10 mV.
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