hydrostatic liquid level sensor

A gauge sensor measures pressure relative to atmospheric pressure, usually through a vent tube in the cable. An absolute sensor measures relative to a fixed vacuum reference and requires barometric compensation from a separate logger or station. For most surface water and groundwater applications, a vented gauge sensor is simpler and cheaper, provided the vent tube is kept dry. For deep submersible uses where the vent cable is impractical, an absolute sensor plus a barometric logger is the standard approach. Kingmach stocks both types and can help you decide based on your deployment depth and data infrastructure.

Condensation in the vent tube can cause zero drift and erratic readings. We recommend several practices: always route the cable with a drip loop near the datalogger, use desiccant cartridges or hydrophobic vents at the logger end, and seal the sensor-end cable entry properly. Some of our cables come with an embedded gel to block moisture migration. If you\u2019re dealing with extreme humidity, switching to an absolute sensor with separate barometric compensation is often the easier long-term fix.

Yes, but material selection matters. For seawater, we typically recommend titanium housings to prevent crevice corrosion. For acids, Hastelloy or special coatings are available. Our standard 316L stainless steel holds up well in many industrial fluids, but we always ask for a fluid chemistry breakdown before specifying. We also offer ceramic sensing elements if metallic diaphragms aren\u2019t suitable. A quick call with our team early on can avoid expensive mistakes.

Typically, accuracy is specified as a percentage of full scale. For a 20-meter sensor with a 0.1% FS accuracy, that\u2019s \u00b12 cm under lab conditions. In the field, temperature effects and long-term stability are more relevant. Our sensors include active temperature compensation, so the temperature error over -10 to 60\u00b0C is often less than 0.2 mA, which translates to about 2.5 cm for a 20-meter 4-20 mA sensor. Long-term stability is usually better than 0.1% FS per year. We recommend calibrating annually if your data demands it.

We do. Modbus RTU on RS-485 is a common option for longer cable runs and when you want to hook up multiple sensors on a single bus. The digital output gives you temperature, pressure, and calculated level directly, plus diagnostic information like sensor voltage. We can also supply SDI-12 versions. Lead time for digital variants is typically the same as analog\u2014just mention it when you inquire.