Kymograph Wilhelm Petzold (0288)
Index: 0288
Year: 1875-1891 ?
Maker: Wilhelm Petzold, Leipzig
Dimensions: 36 x 18 x 62 cm
Info
Originally invented in 1840 by Carl Ludwig for graphing blood pressure changes, the system was later refined for a multitude of tasks, but seems to be used mostly in the medical world of physiology.
This device serves to rotate the drum with a fixed speed by means of a clock mechanism and centrifugal speed control. To the drum, a chart is attached (glued?) and an external apparatus with stylus could then graph the value to be monitored.
Particular to this kymograph is that the drum is also moved laterally to allow for much longer time periods rather than using just one circumference. To obtain this movement, the clockwork also drives an axle that, through 2 gears on top, drives a threaded rod lifting the complete drum mechanism.
To add flexibility to the apparatus, the complete drum unit can be set in different positions from -90 degrees to +90 degrees in steps of 45°.
On the back of the sideplate of the clock mechanism, there is storage for other springs. Presumably used to change the tensioning of the centrifugal mechanism in order to change the drive speed.
Inscription on top rod:
LS 189
Inscriptions on top of clock mechanism:
WILH. PETZOLD
24.
LEIPZIG
On the back of the clock mechanism:
U.B
P
References/Links/More Info
Theory of Science Article from the Czech Academy of Sciences
Max Planck Institute for the History of Science, Berlin - Wilhelm Petzold Kymograph drawing
Images
