Micro Range Hydrostatic Level Sensor

The span is typically configurable down to a few centimeters of water column. The exact minimum depends on the calibration and the signal-to-noise ratio you can tolerate. Many projects use 0–0.5m or 0–1m full scale for very shallow applications.

The vent tube equalizes the back side of the diaphragm with ambient air pressure, so the reading stays true even when barometric pressure changes. It does require that the cable end be kept dry, often inside a weatherproof junction box or datalogger enclosure. Desiccant packs are sometimes placed in that enclosure to reduce moisture ingress through the cable jacket over time.

Yes, as long as the borehole casing diameter accommodates the probe. For very narrow piezometers, we can supply a slimline version. The low range makes it suitable for shallow groundwater monitoring where you need to see small fluctuations that a wide-range sensor would miss.

The most common choices are 4‑20mA (two‑wire) and RS485 with Modbus RTU. SDI‑12 is also an option for integration with certain environmental loggers. The electronics are potted, so the output format is fixed at order time.

In clean water, a drift check every 12 to 18 months is usually enough. In silty or chemically aggressive water, more frequent checks are recommended. The zero point can be verified in the field by lifting the sensor out of the water and confirming the output corresponds to zero depth. If a shift is observed, the sensor can be returned for recalibration.