This system is designed to transduce displacements during contractions and movements into proportional electric currents. The amount of force required to operate the system is exceedingly small, providing ideal isotonic measurement conditions for physiological and pharmacological research. This arrangement of a lever transducer with any bridge system (DC measuring bridge or TAM plug-in module of our PLUGSYS, see page I33) is particularly well suited to isotonic measurements in smooth muscle preparations in isolated organ and tissue baths. Values are transmitted as a result of movements of a permanent magnet within field plates.
The instrument is calibrated by locking the end of the lever into the calibration stops on the frame. These stops represent full deflections of ±10 and ±20 mm. If the organ preparation is attached to hole no. 10, this is equivalent to a movement of ±20 mm (= 40 mm total), reducing for each lower hole used. The unit can be interfaced with almost any type of AC or DC bridge.
There are 3 calibration steps on the frame: ±22 mm, 0 and –22 mm at a distance of 100 mm from the pivot measured at the arch. The calibration amplitude is reduced at the various holes as shown below.