Data Acquisition & Logging
Wireless Air Velocity Sensors
ALTA wireless air velocity sensor measures the pressure difference between two input ports
The ALTA wireless air velocity sensor measures the pressure difference between two input ports, the temperature, and altitude determines the speed at which the air is moving in a system and transmits the measurement to iMonnit.
• Measurement range: -50 m/s to 50 m/s
• Calibrated and temperature compensated
Principle of Operation
The sensor measures the pressure difference between two ports. When viewing the sensor from the top, the right inlet port is the positive or high side pressure input. When the pressure on this port is greater than the left port the sensor produces a negative pressure reading. When the pressure is greater on the left port the sensor produces a positive pressure reading. Combined with the temperature and the altitude, the sensor determines at what rate the air is flowing in a system.
Features of Monnit ALTA Sensors
• Wireless range of 1,200+ feet through 12+ walls *
• Frequency-Hopping Spread Spectrum (FHSS)
• Improved interference immunity
• Improved power management for longer battery life **(12+ years on AA batteries)
• Encrypt-RF® Security (Diffie-Hellman Key Exchange+AES-128 CBC for sensor data messages)
• Onboard data memory stores up to 512 readings per sensor:
- 10-minute heartbeats = 3.5 days
- 2-hour heartbeats = 42 days
• Over-the-air updates (future proof)
• Free iMonnit basic online wireless sensor monitoring and notification system to configure sensors, view data and set alerts via SMS text and email
*Actual range may vary depending on environment.
**Battery life is determined by sensor reporting frequency and other variables. Other power options are also available.
ALTA Commercial Wireless Air Velocity Sensor | Technical Specifications
Supply voltage | 2.7–3.8 VDC (3.0–3.8 VDC using power supply) * | |||||
Current consumption | 0.2 µA (sleep mode), 0.7 µA (RTC sleep), 570 µA (MCU idle), 2.5 mA | |||||
(MCU active), 5.5 mA (radio RX mode), 22.6 mA (radio TX mode) | ||||||
Operating temperature range (commercial version) ** | -18°C to 55°C (0°F to 130°F) with Alkaline Batteries | |||||
-40°C to 85°C (-40°F to 185°F) with Lithium Battery | ||||||
Pressure range | -500 Pa to 500 Pa | |||||
Allowable overpressure | 100 kPa | |||||
Rated burst pressure | 500 kPa | |||||
Max humidity for long-term exposure | 40°C dew point | |||||
Range at 0 m Altitude | 0-30m/s | |||||
Range at 5000 m Altitude | 0-40m/s | |||||
Range at 8000 m Altitude | 0-50m/s | |||||
Span repeatability | 0.5% of reading | |||||
Span shift due to temperature variation | < 0.5% of reading per 10°C | |||||
Offset stability | < 0.05 Pa/year | |||||
Calibrated for | Air, N2 | |||||
Media compatibility | Air, N2, O2, non-condensing | |||||
Temperature measurement range | -40°C to 85°C (-40°F | to +185°F) | ||||
Calibrated temperature measurement range | -20°C to 85°C (-4°F | to +185°F) | ||||
Temperature resolution | 0.1°C | |||||
Temperature accuracy | +/- 2°C (-10°C to +60°C) | |||||
+/- 3°C (-40°C to +85°C) | ||||||
Temperature repeatability | +/- 0.1°C | |||||
Integrated memory | Up to 512 sensor messages | |||||
Wireless range | 1,200+ ft non-line-of-sight | |||||
Wireless operation | 900 MHz—Frequency-Hopping Spread Spectrum | |||||
868 MHz and 433 MHz—Frequency-Agile Wireless | ||||||
Security | Encrypt-RF® (256-bit key exchange and AES-128 CTR) | |||||
Weight | 3.7 ounces |
ALTA Industrial Wireless Air Velocity Sensor | Technical Specifications | ||||
Supply voltage | 2.7–3.8 VDC (3.0–3.8 VDC using power supply) * | |||
Current consumption | 0.2 µA (sleep mode), 0.7 µA (RTC sleep), 570 µA (MCU idle), 2.5 mA | |||
(MCU active), 5.5 mA (radio RX mode), 22.6 mA (radio TX mode) | ||||
Operating temperature range (board circuitry and battery) | -40°C to +85°C (-40°F to +185°F) ** | |||
Included battery | Max temperature range | -40° to +85°C (-40° to +185°F) | ||
Capacity | 1500 mAh | |||
Optional solar feature | Solar panel | 5VDC/30mA (53mm x 30mm) | ||
Charging temperature range | 0° to 45°C (32° to 113°F) | |||
Max temperature range | -20° to 60°C (-4° to 140°F) | |||
Included rechargeable battery | 600 mAh/>2000 charge cycles (80% of initial capacity) | |||
Solar efficiency | Optimized for high and low-light operation *** | |||
Pressure range | -500 Pa to 500 Pa | |||
Allowable overpressure | 100 kPa | |||
Rated burst pressure | 500 kPa | |||
Max humidity for long-term exposure | 40°C dew point | |||
Range at 0 m Altitude | 0-30m/s | |||
Range at 5000 m Altitude | 0-40m/s | |||
Range at 8000 m Altitude | 0-50m/s | |||
Span repeatability | 0.5% of reading | |||
Span shift due to temperature variation | < 0.5% of reading per 10°C | |||
Offset stability | < 0.05 Pa/year | |||
Calibrated for | Air, N2 | |||
Media compatibility | Air, N2, O2, non-condensing | |||
Temperature measurement range | -40°C to 85°C (-40°F to +185°F) | |||
Calibrated temperature measurement range | 0.1°C | |||
Temperature resolution | 0.1°C | |||
Temperature accuracy | +/- 2°C (-10°C to +60°C) | |||
+/- 3°C (-40°C to +85°C) | ||||
Temperature repeatability | +/- 0.1°C | |||
Integrated memory | Up to 512 sensor messages | |||
Wireless range | 1,200+ ft non-line-of-sight | |||
Security | Encrypt-RF® (256-bit key exchange and AES-128 CTR) | |||
Weight | 4.7 ounces | |||
Enclosure rating | NEMA 1, 2, 4, 4x, 12 and 13 rated, sealed and weather proof | |||
UL rating | UL Listed to UL508-4x specifications (File E194432) |
Example Applications
• Building/Room Pressure
• Air Flow
• Variable Air Volume Filter Status
• Duct Pressure
• Clean Rooms
• Hospitals
• Fume Hoods
• Computer Rooms
• Many additional applications