--- title: "Water Pressure Sensors & Monitoring | Aethair" description: "Water pressure is the hydrostatic pressure of the water column above a submerged sensor, the signal behind level and depth. Vented vs. absolute sensors." url: https://aethair.io/parameters/water_pressure/ --- Measurements · Fluid / Level / Flow # Water Pressure Also known as water column, water column pressure, hydrostatic pressure Water pressure, in this context, is the hydrostatic pressure exerted by a column of water above a submerged sensor, reported in units such as centimeters of water (cmH₂O) or pounds per square inch (psi). [Schedule a call](https://calendly.com/d/ctdd-mkr-v9v/aethair-demo-website) [Configure Water Pressure Monitoring](https://aethair.io/build/?params=water_pressure) At a glance cmH₂O Fluid / Level / Flow 1 way to measure it - **Thiamis** 5 external instruments What it is ## What is water pressure? Water pressure, in this context, is the hydrostatic pressure exerted by a column of water above a submerged sensor, reported in units such as centimeters of water (cmH₂O) or pounds per square inch (psi). It is distinct from barometric (atmospheric) pressure: it is the pressure the water itself adds, and it rises in direct proportion to the depth of water above the sensor. Because that relationship is linear and well understood, water pressure is the quantity a submersible transducer actually senses, and water level or depth is derived from it. A reading can be **absolute**, including the weight of the atmosphere pressing on the surface, or **gauge** (vented), where the atmospheric component is canceled at the sensor so that only the water column remains. Because it is what submersible level sensors measure directly, water pressure underpins groundwater, surface-water, and level monitoring wherever a pressure transducer is deployed. Water pressure is the raw signal behind depth and level, so its quality sets the quality of every derived level and flow value. In groundwater monitoring, a downhole transducer records the pressure of the water standing above it, from which the depth to the water table (and thus aquifer behavior, recharge, and the impact of pumping) is calculated. In rivers, tanks, and reservoirs the same principle turns a submerged sensor into a continuous stage or fill-height record. Whether a sensor reads absolute or gauge pressure also matters operationally: an absolute sensor must be paired with a barometric reference so the atmospheric part can be removed, or the derived level will drift with the weather. For hydrologists, groundwater specialists, and site operators, water pressure is therefore the foundational measurement from which level and flow are built. How it is measured ## How Water Pressure Is Measured Water pressure is measured with a **submersible pressure transducer** logged on a Thiamis gateway for continuous measurement. The sensor sits at a known, fixed depth and its diaphragm responds to the pressure of the water column above it. Vented (gauge) sensors run a tube to the surface so that changing atmospheric pressure is canceled at the diaphragm, leaving only the water column. Non-vented (absolute) sensors are simpler and more rugged but record water plus atmosphere, so a separate barometric sensor is used to compensate the record. Transducers are temperature-compensated and referenced to a known elevation, and they need periodic checks against a manual dip because zero drift is the main long-term limitation. An instrument on Thiamis 5 A third-party instrument connected to a Thiamis gateway, reporting into the same Environet account. ### Placing water pressure sensors The transducer is secured at a known, fixed depth at a hydraulically stable point: in a groundwater well, a stilling well, or a sheltered part of a channel or tank away from turbulence and the plunge of inflows that would disturb the reading. Its elevation must stay constant, because the derived level depends on the sensor sitting at the depth it was referenced to; a sensor that shifts or is re-hung without re-referencing will give a false level. Where an absolute sensor is used, a barometric reference is sited nearby so the atmospheric component can be removed cleanly. ### Every device and option that measures Water Pressure 5 | Device / option | Type | Base platform | Measures | | - | - | - | - | | [Van Essen Instruments](https://aethair.io/sensors/van-essen-instruments-water-level-flow/) · Mini-Diver, Cera-Diver, Micro-Diver… | Water Level & Flow | Thiamis | Water Pressure [Conductivity](https://aethair.io/parameters/conductivity/) [Water Temperature](https://aethair.io/parameters/water_temperature/) | | [YSI](https://aethair.io/sensors/ysi-water-quality-sondes/) · EXO1, EXO1S, EXO2… | Water Quality Sondes | Thiamis | Water Pressure [Dissolved Ammonia (NH₃)](https://aethair.io/parameters/ammonia/) [Ammonium (NH₄)](https://aethair.io/parameters/ammonium/) [Blue-Green Algae](https://aethair.io/parameters/bga/) [Chloride](https://aethair.io/parameters/chloride/) [Chlorophyll](https://aethair.io/parameters/chlorophyll/) [Conductivity](https://aethair.io/parameters/conductivity/) | | [In-Situ](https://aethair.io/sensors/in-situ-water-quality-sondes/) · Level TROLL 300, Level TROLL 400, Level TROLL 500… | Water Quality Sondes | Thiamis | Water Pressure [Dissolved Ammonia (NH₃)](https://aethair.io/parameters/ammonia/) [Ammonium (NH₄)](https://aethair.io/parameters/ammonium/) [Blue-Green Algae](https://aethair.io/parameters/bga/) [Chloride](https://aethair.io/parameters/chloride/) [Chlorophyll](https://aethair.io/parameters/chlorophyll/) [Conductivity](https://aethair.io/parameters/conductivity/) | | [Spectra Scientific](https://aethair.io/sensors/spectra-scientific-water-quality-sondes/) · Spectra Litmus 6, Spectra Litmus 4 | Water Quality Sondes | Thiamis | Water Pressure [Dissolved Ammonia (NH₃)](https://aethair.io/parameters/ammonia/) [Ammonium (NH₄)](https://aethair.io/parameters/ammonium/) [Blue-Green Algae](https://aethair.io/parameters/bga/) [Chloride](https://aethair.io/parameters/chloride/) [Chlorophyll](https://aethair.io/parameters/chlorophyll/) [Conductivity](https://aethair.io/parameters/conductivity/) | | [YSI](https://aethair.io/sensors/ysi-water-quality-sondes/) · 6600 V2, 6600EDS V2, 6920 V2… | Water Quality Sondes | Thiamis | Water Pressure [Dissolved Ammonia (NH₃)](https://aethair.io/parameters/ammonia/) [Ammonium (NH₄)](https://aethair.io/parameters/ammonium/) [Blue-Green Algae](https://aethair.io/parameters/bga/) [Chloride](https://aethair.io/parameters/chloride/) [Chlorophyll](https://aethair.io/parameters/chlorophyll/) [Conductivity](https://aethair.io/parameters/conductivity/) | [Configure Water Pressure Monitoring](https://aethair.io/build/?params=water_pressure) Where it is monitored ## Solutions That Monitor Water Pressure Each one links to the solution page showing what that industry measures it for. ### [Hydrology, Level & Flow](https://aethair.io/solutions/hydrology/) Often added Flood warning, stream gauging, and groundwater Related ## More in Fluid / Level / Flow [Water Level / Depth](https://aethair.io/parameters/water_level/) [Volume (totalized)](https://aethair.io/parameters/volume/) [Flow Rate](https://aethair.io/parameters/flow/) [Fluid Differential Pressure](https://aethair.io/parameters/differential_pressure_fluid/) [Fluid Particle Count (ISO 4406)](https://aethair.io/parameters/particle_count_fluid/) [Velocity](https://aethair.io/parameters/velocity/) Questions ## Water Pressure FAQ How is water pressure different from barometric pressure? Barometric pressure is the weight of the atmosphere; water pressure here is the additional pressure exerted by the column of water above a submerged sensor. A vented (gauge) transducer cancels the atmospheric part at the sensor and reads the water column alone, while an absolute transducer reads both and needs a separate barometric measurement to remove the atmospheric component. How does water pressure give water level? The pressure of a water column is directly proportional to its height, so a transducer at a fixed, known depth converts its pressure reading into the depth of water above it. Referencing the sensor to a datum then turns that depth into a water level or stage. What is the difference between vented and absolute sensors? A vented (gauge) sensor has a tube to the surface that cancels atmospheric pressure, so it reads the water column directly; an absolute sensor is sealed and reads water plus atmosphere. Absolute sensors are more rugged and easier to deploy but require a barometric reference to compensate for changing air pressure, otherwise the derived level drifts with the weather. How do I monitor water pressure? Deploy a submersible pressure transducer at a fixed, referenced depth, connected to a Thiamis gateway, logging continuously with periodic manual-dip checks; pair an absolute sensor with a barometric reference. Use the configurator to combine water pressure with water level, flow, and volume for a complete groundwater or surface-water station.