The PRODYN Models SD-S10 and SD-S30 sensors are qs or D. sensors that are equivalent to the AFWL Models HSD-SI and HSD-S3 respectively. These sensors can be used as D-dot sensors or they can be used to measure the time rate-of-change of surface current density. The sensor consists of a hemis-pherical dome supported above a metal mounting surface by a dielectric ring.
The equation pertinent to this device is:
Vo = R Aeq dqs = sensor output (in volts)
dt
where
R = load resistance (50W )
Aeq = sensor equivalent area
qs = surface current density (coul/m2 )
The sensors are passive devices, therefore, an external power source is not required. The sensors
are equipped for purging with a gas such as dry air, nitrogen or SF6.
