Product Description
The Bar series sensors are compact, high-resolution pressure sensors for underwater pressure and depth sensing. The aluminum body uses the bulkhead penetrator form factor, so it’s quick to install in watertight enclosure and is ideal for use on ROVs, AUVs, and other underwater projects.
Two models are available to suit different applications:
The Bar02 is a low-pressure, ultra-high resolution sensor using the Measurement Specialties MS5837-02BA. It measures up to 2 bar (about 10 meters water depth) with a depth resolution of just 0.16 mm and can also measure in-air altitude with 13 cm resolution. This makes it ideal for shallow-water devices where a high level of resolution is required. It includes a temperature sensor accurate to ±2 °C and is supported in ArduSub 4.7 and later.
The Bar30 is a high-pressure sensor using the Measurement Specialties MS5837-30BA. It measures up to 30 bar (about 300 meters water depth) with a depth resolution of 2 mm, making it a great choice for deep-water ROVs and general underwater instrumentation. The built-in temperature sensor has ±4 °C accuracy, and is supported by ArduSub and other ArduPilot firmware.
Both sensors communicate via I²C, operate on 3.3 V logic (with 5.5 V max power input), and come with a JST GH connector compatible with most flight controllers, like the Navigator Flight Controller and Pixhawk autopilot. The electrical schematic and board layout are fully open-source, so you can adapt the design to your own projects.
These sensors use gel-covered sensing elements that must be dried for at least 2 hours each day to maintain accuracy. Long-term submersion may damage the sensor.
| Model | Bar02 | Bar30 |
|---|---|---|
| Electrical | ||
| Supply Voltage (Vin) | 2.5–5.5 V | |
| I²C Logic Voltage (SDA and SCL) | 2.5–3.6 V | |
| Peak Current | 1.25 mA | |
| Performance | ||
| In Air Operating Temperature | -20 to 85°C | |
| In Water Operating Temperature | 2 to 40°C | |
| Maximum Mechanical Pressure1 | 10 bar | 50 bar |
| Operating Pressure (-20 to 85°C) | 0.3–1.2 bar 0.01–2 bar (extended) |
0–30 bar |
| Operating Depth2 | 0–10 m | 0–295.6 m |
| Relative Accuracy | 0 to 60°C: ±2 mbar (±2 cm in fresh water) -20 to 85°C: ±4 mbar (±4 cm in fresh water)3 |
- |
| Absolute Accuracy | – | 0 to 45°C: ±200 mbar (204 cm in fresh water) -20 to 85°C: ± 400 mbar (409 cm in fresh water) |
| Resolution | .016 mbar (1.6 mm in fresh water; 13 cm in air at sea level) | .2 mbar (2 mm in fresh water) |
| Temperature Sensor Relative Accuracy | ±2°C | - |
| Temperature Sensor Absolute Accuracy | – | ±4°C |
| Physical | ||
| Storage Temperature | -40 to 85°C | |
| Maximum Continuous Submersion4 | 24 hrs | |
| Weight in Air | 14 g | |
| Bulkhead Thread | M10 x 1.5 | |
| Installation Hole (Port) Size Clearance |
10.0–10.2 mm | |
| Interfacing | ||
| ArduSub Compatible | Yes (>= 4.7) | Yes |
| Development Libraries |
MS5837 Arduino MS5837 Python MS5xxx AutoPilot | |
| I²C Address | 0x76 | |
| Connector | 4-position JST GH | |
| Mating Connector | (4-pos JST GH available on Digi-Key) | |
| Connector Pinout |
1 - Red - Vin 2 - Green - SCL 3 - White - SDA 4 - Black - GND |
|
1 Maximum mechanical pressure is the highest pressure the sensor can withstand before sustaining permanent damage.
2 Depth values are calculated assuming 1 bar atmospheric pressure and freshwater density (1000 kg/m³); actual values will vary with fluid density.
3 Applies only to standard pressure range. For extended pressure range, please see MS5837-02BA datasheet.
4 Sensing element must be dried for at least 2 hours daily to maintain accuracy; long-term submersion may damage the sensor.
