UEP & ELFE SENSORS

The Polyamp Carbon Fiber Electrodes sensor is very sensitive. The mechanical robustness, handling and longevity of carbon fiber technology sensors make it much more versatile for underwater UEP / ELFE applications compared to electrode type of sensors.  Compared to AgAgCl sensors the stabilisation of sensitivity at deployment is much faster than electrode type of sensors. Making them especially suitable for fast deployable systems (Mines, ROV, signature check before entering mine affacted areas).

Carbon fiber sensor is in fact very sensitive and its noise is lower than the very low noise PA3004 amplifier.  1 nV/m(RoothHz) (5 mHz to 5 kHz)(1). 

In differential versus low-ohmic measurements, the property of sensor is capacitive, which means a virtual DC voltage will occur. For this reason, the amplifier is equipped with a high pass filter (HP 5 mHz) to provide a stable zero level. This HP filter also protects from amplifier saturation, due to DC noise, which is the most common cause of saturation on all types of highly sensitive amplifiers. Therefore, this HP filter is also particularly relevant to the AgAgCl system.

(1) ULF actually 0 - 3 Hz by definition. Our CF-sensor is not usable for passive geological applications, although Earth quakes can be detected. As the propagtion speed of ULF is 0.7 time the speed of light, the signal comes well in advance of underwater accoustic methods.