Products | Systems Division

UEP & ELFE Sensors

UEP and ELFE carbon fibre 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 other types of electrode. 

Carbon fiber sensor is in fact very sensitive and its noise is lower than the very low noise PA3004 amplifier.

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.

UEP Sensor Data
Sensor type



Length 125±5 mm 58 mm
Diameter 50 mm 55 mm
Weight in Air 150 g 130 g
Weight in Water  10 g 10 g


Standard cable  45 cm 45 cm
Optional cable  1 pole connector  1 pole connector
Optional cable length  Up to 50 m Up to 100 cm

The PA3004 very low noise differential amplifier

The Very Low Noise Differential Amplifier PA3004 meets the small area demand for underwater integration platform with flexibility for different types of measurements. PA3004 is optimized for both our carbon fiber type sensors and AgAgCl electrodes. The very wide bandwidth meets the definition ELFE frequency of 0-3000 Hz. However, even in the case of measurements near the field, very rarely usable frequencies above 500 Hz. It emphasizes for signal analysis is actually sensitivity and noise levels at frequencies below 500 Hz.

Important functions of the amplifier

  • Optimized input for Carbon fiber or AgAgCl sensors by switch setting
  • Particularly useful for integration into an underwater survey platform
  • Very low noise with + 80 / + 86 dB gain
  • Sound level 1 nV RootHz @ 1 Hz
  • Linearity <1% 1 to 5000 Hz
  • Selectable 80/60 dB gain relay (-15V)
  • Insulation amplifiers provide excellent shaft separation and common mode noise suppression
  • Up to 4 km analog signal transmission with a line driver voluntarily.