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.
The most important characteristics:
| Eigenperiod | 5 seconds |
| Upper frequency limit | 50 Hz |
| Transduction factor | 800 V/m/s (differential) |
| 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 |
