BRUEL & KJAER 2305 - Paper Holder System Functionality

The coil assembly is mounted in the magnet system by means of the three
screws marked S in Fig. 1.10. If, for any reason, it should be desired to
remove the coil assembly from the magnet, this can be readily done by
unscrewing the screws S and pulling the 'coil assembly out, together with
the center pole piece.
NOTE: During dismantling the coil assembly care should be taken that the
magnetic field in which the coil normally moves, is not at any instant
opened. This can be obtained by either substituting the coil assembly with an
iron rod with the same dimensions as the center pole piece or by mounting
an external iron tube around the magnet.
Mechanical. The driving arm of the moving coil assembly is connected to
the
mechanical writing system by means of a wishbone spring head, the
system being so designed to give a free choice of 100 mm or 50 mm writing
width. By fixing the wishbone in one of the two different holes in the
mechanical writing system, the drive arm will propel the bogie with the
penholder to traverse 100 mm or 50 mm paper respectively.
The penholder can hold both sapphires and inking pens . The pressure of the
mounted sapphire or pen on the recording paper can be adjusted by a
screw
J (Fig. 3.1 page 31).lt is pre·adjusted at the factory and will normally
amount to around 15 grammes. *)
Paper Holder System.
(ReIer Fig. 3.1 on page 31).
To allow accurate alignment of the zero line on the paper with the zero
mark on the mechanical writing system scale, the scale which is spring.
loaded is adjustable by a tension screw on the right-hand side of the writing
arm unit. A cam screw K located on the scale varies the pressure of the paper
guide clip E, thereby allowing a variety of paper thicknesses to be used. More
details
about the various methods of alignment can be found under Operation.
A demountable stainless steel cutting blade supplied with the Recorder is
inserted at the front plate beneath the writing plate in order to give clean
detachment of recorded paper from the roller. It is so spaced that provided
one of the frequency calibrated papers QP 0123, QP 0223, QP 0323 or
QP 1123 is used, and the Recorder is stopped prior to detachment in a
position so that the writing system stylus rests around the 10 Hz (cis) line on
the
next chart, the recording will always be detached including the formal
which allows object measured, paper speed etc. to be noted .
*) For the paper types QP 0402 and QP 0423 the pressure should be readiusted to around
20 grammes.
IH