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Pressure probe with conductivity measurement cell

The OTT PLS-C measures water conductivity, level, and temperature in both surface and groundwater applications with a robust ceramic pressure cell and 4-electrode conductivity cell. Its extremely low power consumption makes it ideal for long-term deployment, particularly at solar powered measuring stations for ground-and surface waters.

  • Surface water, Groundwater
  • Vented pressure cell and 4-electrode graphite conductivity cell
  • Water level, Pressure, Conductivity, Temperature
  • Water level, temperature, and conductivity measurement - for use with external data logger
  • No
  • SDI-12 or RS-485 (using SDI-12)
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Outputs for conductivity include specific conductivity, salinity, and total dissolved solids

  • The robust ceramic pressure cell offers industry-leading accuracy and does not deform over time like membrane technology, providing long-term measurement stability
  • Rugged design: Ceramic pressure cell resistant to physical force (4 x burst pressure) and enclosure made of high-quality saltwater resistant steel for use in coastal environments
  • Vented pressure probe, automatically compensates for changes in barometric pressure
  • Robust cable with Kevlar core for length stabilization and capillary tube for venting
  • Built-in microcontroller – compensates for temperature effects and applies correction values for gravitational acceleration or water density
  • Simple setup and connection to external dataloggers using SDI-12

Water level, temperature, and conductivity measurement of:

  • Groundwater wells
  • Streams, rivers, channels, and canals
  • Reservoirs, lakes, and wetlands

Ideal for monitoring:

  • Continuous monitoring networks
  • Short-term or long-term projects
  • Salt water intrusion
  • Aquifer storage and recovery
  • Estuaries and wetlands
Data Sheet - OTT PLS-C - EN
Operating Instructions Pressure Probe with Conductivity Sensor OTT PLS-C
OTT Groundwater Sensor Selection Guide
OTT PLS-C - CE Konformitätserklärung | Declaration of Conformity | Declaration de Conformité
Technical Note - Sensor Selection Guide Surface Water
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Output parameters Water level/pressure, temperature, specific conductivity, salinity, TDS
Water level measurement (pressure)
Pressure sensor ceramic, temperature-compensated
Measuring range 0 ... 4 m, 0 ... 10 m, 0 ... 20 m, 0 ... 40 m, 0 ... 100 m water col.
Resolution 0.001 m; 0.1 cm; 0.01 ft; 0.1 mbar; 0.001 psi
Accuracy (linearity + hysteresis) ≤ ± 0.05 % FS
Long-term stability (linearity + hysteresis) ≤ ± 0.1 %/a FS
Zerodrift ≤ ± 0.1 % FS
Pressure sensor capability to withstand overloads without permanent mechanical damage ≥ 4 x measuring range
Temperature-compensated operating range -5 °C ... +45 °C (ice free)
Units m, cm, ft, mbar, psi
Temperature measurement
Sensor NTC
Measuring range -25 °C ... +70 °C (ice free)
Calibrated range +5 °C ... 45 °C
Resolution 0.01 °C
Accuracy ±0.1 °C
Units °C, °F
Conductivity measurement
Sensor 4 graphite electrodes
Calibrated range +5 °C ... 45 °C
Measuring range 5 ... 2.000 µS/cm
Resolution 1µS/cm
Accuracy ±1 µS/cm or ± 0.5 % of measured value (whichever is higher)
Unit µS/cm
Measuring range 0.1 ... 100 mS/cm
Resolution 0.01 mS/cm
Accuracy ± 0.01 mS/cm or ±1.5 % of measured value (whichever is higher)
Unit mS/cm
Temperature compensation, conductivity freshwater, saltwater, standard method 2510, ISO 7888/EN27888
Salinity calculation Standard method or USGS 2311
Electrical data
Supply voltage 6 ... 27 V DC, typically 12/24 V DC
Power consumption
SDI-12 sleep-mode <30 µAV
SDI-12 active-mode <32 mA
Interfaces SDI-12, RS-485 (SDI-12 protocol)
Mechanical data
Probe (Ø x h) 317 mm x 22 mm
Cable length SDI-12: 1 ... 100 m
RS-485: 1 ... 1000 m
Housing material probe POM, stainless steel
(DIN 1.4539, 904 L ), resistant to sea water
Cable jacket PUR
Probe approx. 0.43 kg
Probe cable approx. 82 g/m
Ambient conditions
Storage temperature - 40 °C ... + 85 °C
Type of protection Probe: IP 68
EMC limits EG 2004/108/EG, EN 61326-1:2013
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