Hydrostatic Level Probe For Measurement Of Waste Liquid Levels – Aplisens SGE-25S And SGE-25C Series


  •  Any measurement range from 2 up to 20 m H2O
  •  Integrated internal overvoltage protection circuit
  •  ATEX Intrinsic safety
  •  Marine certificate DNV

Principles of operation, design
The probe measures liquid levels, basing on a simple relationship between the height of the liquid column and the resulting hydrostatic pressure. The pressure measurement is carried out on the level of the separating diaphragm of the immersed probe and is related to atmospheric pressure through a capillary in the cable. The use of a special separator with a large uncovered diaphragm minimizes the metrological effect of sediment deposit on the diaphragm surface. This enables the probe long lifetime and proper work in contaminated media (even in the presence of abrasives, such as sand) and facilitates cleaning with delicate stream of running water (washing with water under pressure may damage the probe). The active sensing element is a piezoresistant silicon sensor separated from the medium by an isolating diaphragm. The electronic amplifier, which works in combination with the sensor, and is meant to standardize the signal, is additionally equipped with an overvoltage protection circuit, which protects the probe from damage caused by induced interference from atmospheric discharges or from associated heavy current engineering appliances.

The SGE-25S and SGE-25C probes are applicable to measure levels of liquids containing contaminants or suspensions. A typical use for this probe is the measurement of levels of liquid waste in intermediate pumping stations, fermentation chambers, settling tanks etc.


Measuring Range 2.5 m H2O 4 m H2O 0…10 m H2O ÷ 20 m H2O
Overpressure Limit
(repeatable – without hysteresis)
20 × range 20 × range 10 × range
Accuracy % FSO acc. to IEC 60770 1% 1% 0.50%
Accuracy % FSO acc. to BFSL 0,75% 0.50% 0.25%
Thermal error of zero Typical 0.4% / 10°C
max 0.6% / 10°C
Typical 0.2% / 10°C
max 0.3% / 10°C
Thermal error of span Typical 0.3% / 10°C
max 0.4% / 10°C
Typical 0.2% / 10°C
max 0.3% / 10°C
Hysteresis, repeatability 0,05%
Thermal compensation range 0 ÷ 40°C – standard
-10 ÷ 70°C – special version
Electrical parameters
Medium temperature range -25 ÷ 40°C – standard
0 ÷ 75°C – ETFE and PTFE version
Output signal 4 ÷ 20 mA, two wire transmission
Special version 0 ÷ 10 V three wire transmission (not applicable to Ex)
Load resistance (for supply output) R≥20kΩ
Power supply 8 ÷ 36 VDC (Ex: 9…28 VDC)
TR version: 10.5÷ 36 VDC (Ex: 10.5…28 VDC)
13 ÷ 30 VDC (for 0 ÷ 10 V output)
Error due to supply voltage changes variation 0.005% / V
Degree of protection IP-68
Material of casing and diaphragm SG-25S (casing SS316L, diaphragm SS316L /option Hastelloy C/)
SG-25C (casing SS316L, diaphragm SS316L)
Cable shielding PU, ETFE, PTFE


Aplisens SGE-25S and SGE-25C Hydrostatic level probes for measurement of waste liquid levels-DpstarGroup