Made in the USA
No wiring into a panel, no controller to program, no transmitter loop to power.
Run tubing from the high side and the low side onto the two barbed nozzles, P1 and P2. The sensor reports the difference between them, positive or negative.
Wall-mount or magnet-mount the enclosure nearby. Run it on the D-cell with Supercap, or use the external-power option for a permanent install.
The sensor joins a self-forming, self-healing network, up to 2-mile line-of-sight range with the on-board antenna.
Browser dashboards, threshold alerts, and CSV export through the Atrium gateway. Set a limit and let it tell you when the cascade slips.
NCD builds three wireless pressure sensors, and they differ in exactly one thing: the pressure they are built to read. Pick by the size of the number you expect to see.
Pair the sensor with an Atrium Gateway, open a browser on your network, and drag the readings you care about onto a dashboard. No code to write.
What this sensor does that a general-purpose pressure transducer cannot.
Resolution reaches 0.03 Pa, and the sensor still detects below 0.02 Pa, less than one ten-thousandth of an inch of water column. Cleanroom, duct and draft pressures are written in these units because the differences that decide the outcome really are this small.
The changes that matter arrive small and early: a room offset slipping by a pascal or two, a filter bank loading a little more each week. This sensor separates those from noise instead of averaging them away, so a trend is visible while it is still only a trend.
Two ports and a signed reading between them across a full scale of ±500 Pa. A room that swings from positive to negative needs no second sensor and no re-plumb, the number simply changes sign.
The sensing element is a medical-grade digital differential sensor from the Sensirion SDP800 family, specified with no offset drift. Low-range instruments are notorious for wandering off between calibrations, and a zero you cannot trust makes every small reading meaningless.
An integrated temperature sensor reports alongside every pressure reading, so a shift in differential can be read against the air temperature that may have caused it. One device, two measurements, one battery.
Up to 2 miles line-of-sight on the on-board antenna, with 128-bit AES encryption and an open communication protocol. Sensors relay for each other, so a mechanical room across the campus still reports in.
Update firmware over the air across the fleet. No ladders, no ceiling tiles, no pulling sensors out of a cleanroom to plug them into a laptop.
| Measurement Type | Bidirectional differential, positive and negative pressure across two ports |
| Pressure Range | Up to ±500 Pa (±2 inch H₂O / ±5 mbar) |
| Pressure Resolution | Up to 0.03 Pa |
| Lowest Detectable Pressure | Less than 0.02 Pa |
| Offset Drift | No offset drift |
| Sensing Element | Sensirion SDP8xx-series digital differential pressure sensor (medical grade) |
| Pressure Ports | Two ports, P1 and P2, with two barbed nozzles included |
| Compatible Media | Air, N₂, O₂, non-condensing and inert gases (non-aggressive gases only) |
| On-Board Temperature | Integrated temperature sensor, reported alongside pressure |
| Temperature Resolution | 2 °C |
| Operating Temperature Range | -20 °C to +85 °C (-4 °F to +185 °F) |
| Protocol | Long-range self-healing wireless mesh |
| Frequency Bands | 868 MHz / 900 MHz / 2.4 GHz |
| Band class | Sub-GHz (868 / 900 MHz), sub-gigahertz radio travels farther and penetrates walls and equipment far better than higher-frequency Wi-Fi or Bluetooth |
| Range (line of sight) | Up to 2 miles (900 MHz on-board antenna) |
| Encryption | 128-bit AES |
| Integration | Open communication protocol (no proprietary lock-in), AWS, Azure, MQTT, Node-RED, or any modern interface |
| Battery | D-cell with Supercap |
| Battery Life | Up to 5 years (interval & environment dependent) |
| Transmission Lifetime | 500,000 wireless transmissions |
| Power Options | Battery, or optional external power |
| Transmission Interval | User-defined, the sensor reports on the schedule you set |
| Firmware | Over-the-air (OTA / FOTA) updates across the mesh |
| Mounting | Wall-mount or magnet-mount |
| Antenna | On-board antenna |
| Part Number | PR55-24 |
| Compliance | RoHS |
Differential pressure is how a building tells you whether air is still going where you designed it to go. These are the places a few pascals decide the outcome.
Cleanroom & Room PressurizationCleanrooms, isolation rooms, and compounding suites hold a small positive or negative offset against the corridor. Lose the cascade and containment is gone while the room still looks perfectly normal.
Filter Banks & Baghouse LoadingPressure drop across a filter climbs steadily as it loads. Watching that rise turns filter changes from a date on a calendar into a decision the equipment makes for you.
Fume Hoods & ContainmentA hood that has stopped pulling looks identical to one that is working. Face-velocity problems register as a differential long before anyone downstream notices a smell.
Air Flow & Duct VelocityAcross an orifice plate, a pitot tube, or a flow station, velocity is a differential pressure measurement. Read it wirelessly instead of walking the duct run with a manometer.
Heat Recovery & VAV ControlEnergy recovery wheels, plate exchangers, and variable-air-volume boxes all depend on a pressure relationship holding. Trend it and you can see a box drifting out of control authority.
Gas Boilers, Stoves & Fuel CellsCombustion air and flue draft live in inches of water. A small change in draft changes the burn, and it shows up on a differential reading before it shows up in efficiency numbers.
Isolation Rooms & Operating TheatresAn isolation room has to stay on the correct side of the corridor, and an operating theatre on the other. Both are held by a handful of pascals, and a door left propped or a filter loading up can undo either one without anything looking wrong from the hallway.
Data Center Containment AislesCold aisle to hot aisle is a small offset in either direction, and which direction it goes tells you whether you are bypassing air or recirculating it. Restricted airflow through a loading CRAC filter turns into a hot spot before it turns into an alarm.
Stairwell & Atrium PressurizationStairwell pressurization is a life-safety system that is tested once a year and trusted the rest of the time. Reading the differential continuously means a fan or damper that has quietly stopped holding the offset is found in the same week, not at the next inspection.
The math is simple. One purchase versus compounding monthly fees.
Pressure across the filter or room is one reading. These sensors cover the air and the fan that moves it, on the same Atrium gateway.
Particulate Matter SensorMount it downstream of the filter. Particle counts show what the filter is letting through.
CO2 Temperature Humidity SensorMount it in the room the system serves. CO2 shows whether the air change is keeping up with the people in it.
Smart Vibration SensorMount it on the supply or exhaust fan motor. A failing bearing shows up weeks before the airflow drops.
Answers to the most common questions about wireless precision differential pressure sensing.
It is a battery-powered industrial wireless sensor from NCD that measures the pressure difference between two ports, in both directions, down to a resolution of 0.03 Pa. It covers a full scale of ±500 Pa (±2 inch H₂O / ±5 mbar), reports temperature alongside every pressure reading, and reports over a long-range self-healing wireless mesh.
Differential means the sensor reports the difference between two pressures rather than either one on its own, and bidirectional means that difference can be read as positive or negative. Connect the two ports across a filter, a wall, or a flow element, and the sensor tells you which side is higher and by how much, so a room that flips from positive to negative pressure is caught without changing anything about the installation.
Pressure resolution reaches 0.03 Pa and the lowest detectable pressure is below 0.02 Pa. That is the point of the precision sensor: general-purpose industrial pressure sensors work in PSI, and everything happening inside a cleanroom or a duct at these levels would read as zero on one of them.
The sensor’s full scale of ±500 Pa is the same as ±2 inch H₂O and ±5 mbar. HVAC and cleanroom specifications are usually written in inches of water, so a room offset called out as 0.05 inch H₂O is about 12 Pa, comfortably inside this sensor’s range and hundreds of times larger than its resolution.
No. The sensing element is a medical-grade digital differential pressure sensor from the Sensirion SDP800 family, specified with no offset drift. Holding zero is the hard part at these pressures, and it is the reason this element was chosen over a general-purpose transducer.
Both ports are for air, nitrogen, oxygen, and other non-condensing, inert, non-aggressive gases. It is not built for liquids, steam, condensing service, or corrosive gases. If your application involves a liquid or a higher-pressure line, the wireless pressure and temperature sensor with its stainless diaphragm is the right sensor instead.
The sensor ships with two barbed nozzles, one for each port. Run tubing from the high-pressure side onto P1 and the low-pressure side onto P2, then wall-mount or magnet-mount the enclosure nearby. There is no controller to program and no loop to power, so a typical installation is tubing, a battery, and a place on the wall.
Yes. An integrated temperature sensor reports alongside every pressure reading, at a resolution of 2 °C over an operating range of -20 °C to +85 °C. Both values arrive in the same transmission, so pressure history and air temperature can be read against each other in the same dashboard.
Up to 2 miles line-of-sight with its on-board 900 MHz antenna. Because the sensors form a self-healing wireless mesh, they relay for each other, so one Atrium gateway can collect readings from a mechanical penthouse, a basement, and a building across the lot. Transmissions are protected with 128-bit AES encryption.
The sensor runs on a D-cell with Supercap and delivers up to 5 years of battery life, with an operational lifetime of 500,000 wireless transmissions. Actual life depends on the transmission interval you set and on environmental conditions. An external power option is available for permanent installations.
There are no monthly fees and no recurring software costs. Readings flow through the Atrium gateway, which supports AWS, Azure, MQTT, Modbus, Node-RED, and a REST API, and the sensor’s open communication protocol means no proprietary lock-in. Pressure data can be pushed into an existing building management, SCADA, or notification platform, or kept entirely on your own network.
The IoT Long Range Wireless Precision Pressure Sensor Bidirectional Differential is made in the USA and is RoHS compliant. It is built and supported by NCD, a manufacturer trusted by more than 7,000 customers worldwide for industrial wireless sensing.
We publish our prices. There is no quote form, no login and no sales call between you and the number.
No, and that is the point of it. Plus or minus 500 Pa, about plus or minus 2 inches of water column, is the entire range, which is what makes it precise enough for room pressure and filter loading. Anything stronger saturates it, and the media is limited to air, nitrogen, oxygen and inert non-condensing gases. For higher pressures our other differential sensors cover PSI-scale ranges.
Our engineers answer in public on the community forum, and the thread stays up for the next person with the same question.
Ask on the NCD Community ForumOne purchase. Full ownership. Precision differential pressure monitoring with nothing to renew.
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