BRUEL & KJAER 2305 - Cam Discs for Drive Shaft II; Turntable Type 3921 for Polar Recording

Cam Discs for Drive Shaft II
For operating the Two-Channel Selector the following cam discs are delivered
with
the Level Recorder.
Short cam (pointed)
2 X 90· cam
1 X 180° cam
OD0060
OD 0061
OD 0059*)
Turntable Type 3921 for Polar Recording.
2 pieces
2
2
By
combining the Level Recorder with the B & K Turntable Type 3921 a
complete polar recorder is obtained allowing various types of directional
characteristics to be automatically recorded . The characteristics are presented
on polar paper Type QP 5102 (vide Fig . 4.1 on p. 44) which is for ink writing
and preprinted in geometrical degrees (0-360°) , being graduated for each 10°.
The radial width of the preprint is 100 mm. An explanation to how the paper
is loaded in the Recorder is given on page 32 .
Fig. 4.4. Turntable Type 3921.
Design. The table plate has a diameter of 354 mm and contains threaded
holes (UNF 10-32 and M5) for fixing test sp e cimens . Additionally it is furnished
with a chuck mounted in the center, which is capable of clamping rods of
diameter up to 16 mm . When it is desired to use a plain table plate the
chuck can be unscrewed. The Turntable is driven by a built-in synchronous
motor via an electromagnetic clutch and gear wheels giving the table an
r.p.m. of 0.75. When th e PAPER SPEED on th e Level Rec ord cr is set to
10 mm /sec. the polar pap er on the Hecorder and the table are in synchronism
as the synchronous motors in the Turntable and the Recorder are driven at
the
same line frequen cy. When the Turntable and the Recorder are connected
*) Mounted on the Recorder.
46