The LE-3D/5s MkIII is the runner-up in popularity after LE-3Dlite MkIII. With an extended low-frequency sensitivity (eigenperiod 5 seconds) and a flat transfer function up to 50 Hz, LE-3D/5s MkIII has been found to be the ideal compromise between portability, ruggedness, and bandwidth, especially for H/V (Nakamura method) measurements. Like LE-3Dlite MkIII, the /5s instruments are factory calibrated to a very narrow tolerance so that one seismometer behaves like any other - no need to keep detailed records about which sensor was connected to which datalogger at which time.

LE 3D 5s

 

The most important characteristics:

Eigenperiod  5 seconds
Upper frequency limit 50 Hz
Transduction factor 800 V/m/s (differentiall)
Output signal 3 analog voltages, max. +- 7V
Power supply +10 ... +16V DC, typically 7 mA @12 V 
Dimensions 195 mm diameter, 165 mm height (excluding handle)
Weight 6.5 kg
Temperature range -15 ... +60 °C
RMS noise @ 1 Hz       < 1 nm/s
Dynamic range > 140 dB