BRUEL & KJAER 2305 - DC Recording

Example:
Deflection of stylus: 40 dB
INPUT ATTENUATOR: 20 dB
The deflection of the stylus thus corresponds to:-
40 dB + 20 dB = 60 dB reo 10 mV = 10 V.
C. DC RECORDING.
I. Calibration.
When recording DC voltage , calibration has to be done against an external
calibrated DC source .
1. Set POTENTIOMETER RANGE to "50" .
2. Set RECTIFIER RESPONSE to "DC".
3. Set LOWER LIMITING FREQUENCY to "50".
4. Set WRITING SPEED to:-
400 mm/sec. (large figures) with 50 mm paper.
800 mm /sec. (small figures) with 100 mm paper.
5. Set PAPER DRIVE to "Stop" and "Forward".
6. Make sure that the SINGLE CHART.-CONT . RECORD pushbutton is
in its released (upper) position.
7. Set POWER to "On".
8. Set MOTOR to "On".
9. Allow a few minutes to warm-up.
10 . Make a suitable deflection of the stylus against the external cali-
brated DC source by adjustment of the INPUT ATTENUATOR and
INPUT POTENTIOMETER.
II. Adjustment to tbe Signal.
1. Lift the Pen/Sapphir e hy the MECHANICAL LIFTING CAM A (Fig.
3.1).
2. Apply the signal to be recorded to the INPUT terminal.
3. LOWER LIMITING FREQUENCY and WRITING SPEED are set to
positions whichever are desired for the recording.
NOTE: Fig. 2.2 on page 24 can be utilized when it is remembered
that LOWER LIMITING FREQUENCY should always be
kept below position "200", and that the highest values of
WRITING SPEED, stated for the various settings of LOWER
LIMITING FREQUENCY, should be avoided.
4. INPUT ATTENUATOR is positioned so that a suitable deflection on
the recorrling paper is ac hieved .
III. Recording.
Refer item III. Recording on page 38 and follow the instructions stated .
The operation procedure outlined above is recommended as a guide, and
whenever particular recordings are to be made , or the Recorder is used
in conjunction with other B & K instruments, the reader is referred to the
40