Photonic Associates Torsion Pendula

During the development of the microthruster, we developed, calibrated and used three different torsion pendula. In the research phase, when we were interested in testing the pulsed laser impulse response of small samples of prospective target materials, some of the most sensitive torsion pendula ever created were used.

In the development phase, when it was necessary to suspend the entire microthruster from the device to measure its thrust, a much sturdier device was developed.

The table below shows the response and sensitivity of each version:

Version	Response	Sensitivity	Range	Readout
High sensitivity device	7 micro-N-s/radian	100 pico-N-s	2 micro-N-s	Laser beam /mirror
Medium sensitivity device	36 micro-N-s/radian	5 nano-N-s	2 micro-N-s	Laser beam/mirror
High capacity (1)	40 milli-N/radian	2 micro-N	40 milli-N	Laser beam/mirror
High capacity (2)	1.3 milli-N/radian	25 nano-N	100 micro-N	Laser beam/ interferometric display

Click the links for further details on the high sensitivity device and and the high capacity device.