Keller AG für Druckmesstechnik offers probes to monitor groundwater levels and filling levels in tanks that can be used under a wide range of conditions.
Depending on requirements, these probes provide fully autonomous operation or they can be used with an integrated data logger, wireless transmission (GSM), an ambient pressure-compensating capillary or a separate absolute pressure sensor; additional options include integrated temperature measurement, etc. Depending on the sounding tube, probe diameters of 16 mm and 18 mm up to 22 mm are available.
Thanks to its diameter of only 16 mm, the DCX-16 can be used in locations where every millimeter counts (e.g. for sounding tubes with small diameters). The pressure sensor is welded into the logger housing. Type DCX-16, which is screwed in position and is fully watertight, operates as an autonomous battery-powered data collector with an absolute pressure sensor.
In shallow water, a second logger (barometer) can be used for separate recording of the barometric pressure on the surface. The differential pressure and/or the filling level are then calculated in the PC by subtraction of the time-stamped measurement data from the individual loggers.
Version DCX-16 SG/VG provides a cable connection, wherein barometric pressure is fed to the sensor as a reference, via a pressure-compensating capillary in the connecting cable. There is no need to remove these loggers from the sounding tube in order to read the data. The interface plug is secured on the sounding tube with a fixing device.
The fully-welded DCX-18 (diameter: 18 mm) is designed as an autonomous level logger for low-cost, long-term measurements of level and temperature, with rechargeable accumulator-type batteries. The microprocessor electronics compensate for linearity and temperature deviations by the pressure sensor, achieving a further increase in the accuracy of the pressure and temperature signals. Different operating modes, with an absolute pressure sensor or an overpressure sensor with a pressure-compensating capillary, can also be supplied for the DCX-18.