Triaxial geophone LE-3D / 5s MKIII
The triaxial sensor LE-3D / 5s MkIII is a triaxial geophone of 5s periode. It’s the ideal sensor for performing H/V measurements background noise. It’s a good solution between protability, robustness ans measurement range [0,15Hz-50Hz]. The LE-3D / 5S can thusbe deployed quickly to perfom seismic microzoning for example.
The LE-3D/5s sensir is composed of electronically compensed 2Hz geophones. The compensation is done analogically (dynamic >140dB)
Lennartz sensors are very stable over time. In addition they do not need to be blocked when transporting equipment and do not need to be calibrated before measurement. (The sensor is ready for sue a few seconds after ignition)
Diameter : 195 mm ; hauteur : 165 mm.
Weight : 6.5 kg.
measurement range : [0.15—50 Hz].
Signal to noise ratio 1 Hz : < 1nm/s.
Dynamic : >140 dB.
Transducerr : 800V/m/s (precisely adjusted).
Amortization: 0.707 (precisely adjusted).
Power supply : 10-16 V DC (Power supply by the seismograph possible).
Consumption : 7mA.
Operating temperature : -15°C à +60°C.
Manufacturer : Lennartz Electronic (Allemagne).
The sensor tolerance allows it to be used with anu seismograph. The LE-3D/5Sb sensor consumes very little (7mA) and is powered directly by the seismograph.
The compensation parameters of geophones are know precisely for each sensor and given their very low signal/noise ratio. Its possible to deconvolute the signal up to a period of 20s (0.05Hz), or even beyond.
H/V measurements background noise : The LE-3D/5s MKIII sensor can be used with a SIGMA4-3way seismograph to perfom H/V measurements to estimate the resonance frequency of a site. (thickness of a filling sedimentary seismic microzonation)