Part Numbers
RXW-SMC-900 • RXW-SMC-868 • RXW-SMC-922 • RXW-SMC-921
HOBOnet Soil Moisture EC-5 Sensor
Important Information
A complete system requires at least one HOBO RX3000 Remote Monitoring Station, a HOBOnet Wireless Manager, and a HOBOnet Wireless Sensor OR one HOBO MicroRX Station (which has an integrated HOBOnet Wireless Manager) and a HOBOnet Wireless Sensor. HOBOnet Wireless Repeaters (RXW-RPTR-xxx or RXW-RPTR-B-xxx) can be added to extend the range.
Overview
Integrates the field-proven ECH2O™ EC5 Sensor and provides readings directly in volumetric water content. This sensor's high-frequency design minimizes sensitivity to salinity and textural effects, and gives it a wide measurement range.
HOBOnet wireless sensors communicate data directly to the HOBO RX3000 or the HOBO MicroRX station, or pass data through other wireless sensors back to the central station. They are preconfigured and ready to deploy, and data is accessed through HOBOlink, Onset's innovative cloud software platform.
Features
Sensor Features
- ±3% accuracy in typical soil conditions, and ±2% accuracy with soil-specific calibration
- Measures a 0.3-liter volume of soil for taking readings at a specific depth or in a container
- High-frequency (70 MHz) circuit provides good accuracy even in high-salinity and sandy soils
Wireless Features
- 900 MHz wireless mesh self-healing technology
- 450 to 600 meter (1,500 to 2,000 feet) wireless range and up to five hops
- Up to 50 wireless sensors or 336 data channels per HOBO RX station
- Simple button-push to join the HOBOnet wireless network
- Onboard memory to ensure no data loss
- Powered by rechargeable AA batteries and built-in solar panel
Specifications
RXW-SMC-xxx | RXW-SMD-xxx | |
Measurement Range | In soil: 0 to 0.550 m³/m³ (volumetric water content) | In soil: 0 to 0.570 m³/m³ (volumetric water content) |
Extended Range | -0.401 to 2.574 m³/m³; see Note 1 | -0.659 to 0.6026 m³/m³; see Note 1 |
Accuracy | ±0.031 m³/m³ (±3.1%) typical 0 to 50°C (32° to 122°F) for mineral soils up to 8 dS/m and ±0.020 m³/m³ (±2%) with soil specific calibration; see Notes 2 and 3 | ±0.033 m³/m³ (±3.3%) typical 0 to 50°C (32° to 122°F) for mineral soils up to 10 dS/m and ±0.020 m³/m³ (±2%) with soil specific calibration; see Notes 4 and 5 |
Resolution | 0.0007 m³/m³ (0.07%) | 0.0008 m³/m³ (0.08%) |
Volume of Influence | 0.3 liters (10.14 oz) | 1 liter (33.81 oz) |
Sensor Frequency | 70 MHz | 70 MHz |
METER ECH2O Probe Part No. | EC-5 | 10HS |
Sensor Operating Temperature Range | 0° to 50°C (32° to 122°F). Although the sensor probe and cable can safely operate at below-freezing temperatures (to -40°C/F), the soil moisture data collected at these extreme temperatures is outside of the sensor’s accurate measurement range. | 0° to 50°C (32° to 122°F). Although the sensor probe and cable can safely operate at below-freezing temperatures (to -40°C/F), the soil moisture data collected at these extreme temperatures is outside of the sensor’s accurate measurement range. Extended temperatures above 50°C (122°F) will decrease mote battery life. |
Wireless Mote | ||
Operating Temperature Range | -25° to 60°C (-13° to 140°F) with rechargeable batteries -40° to 70°C (-40° to 158°F) with lithium batteries |
|
Radio Power | 12.6 mW (+11 dBm) non-adjustable | |
Transmission Range | Reliable connection to 457.2 m (1,500 ft) line of sight at 1.8 m (6 ft) high Reliable connection to 609.6 m (2,000 ft) line of sight at 3 m (10 ft) high |
|
Wireless Data Standard | IEEE 802.15.4 | |
Radio Operating Frequencies | RXW-SMC-900 and RXW-SMD-900: 904–924 MHz RXW-SMC-868 and RXW-SMD-868: 866.5 MHz RXW-SMC-921 and RXW-SMD-921: 921 MHz RXW-SMC-922 and RXW-SMD-922: 916–924 MHz |
|
Modulation Employed | OQPSK (Offset Quadrature Phase Shift Keying) | |
Data Rate | Up to 250 kbps, non-adjustable | |
Duty Cycle | <1% | |
Maximum Number of Motes | Up to 50 wireless sensors or 336 data channels per one HOBO RX station | |
Logging Rate | 1 minute to 18 hours | |
Number of Data Channels | 2 | |
Battery Type/ Power Source |
Two AA 1.2V rechargeable NiMH batteries, powered by built-in solar panel or two AA 1.5 V lithium batteries for operating conditions of -40° to 70°C (-40° to 158°F) | |
Battery Life | With NiMH batteries: Typical 3–5 years when operated in the temperature range -20° to 40°C (-4°F to 104°F) and positioned toward the sun (see Deployment and Mounting), operation outside this range will reduce the battery service life With lithium batteries: 1 year, typical use |
|
Memory | 16 MB | |
Dimensions | RXW-SMC-xxx soil probe: 89 x 15 x 1.5 mm (3.5 x 0.62 x 0.06 in.) RXW-SMD-xxx soil probe: 160 x 32 x 2 mm (6.5 x 1.25 x 0.08 in.) Cable length: 5 m (16.4 ft) Mote: 16.2 x 8.59 x 4.14 cm (6.38 x 3.38 x 1.63 inches) |
|
Weight | RXW-SMC-xxx sensor and cable: 180 grams (6.3 oz) RXW-SMD-xxx sensor and cable: 190 grams (6.7 oz) Mote: 223 g (7.87 oz) |
|
Materials | Sensor: Weatherproof Mote: PCPBT, silicone rubber seal |
|
Environmental Rating | Mote: IP67, NEMA 6 | |
Compliance Marks |
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Note 1:(RXW-SMC-xxx and RXW-SMD-xxx) The sensor is capable of providing readings outside the standard volumetric water content range. This is helpful in diagnosing sensor operation and installation. See the Sensor Operation section for more details.
Note 2: (RXW-SMC-xxx) This is a system level accuracy specification and is comprised of the probe’s accuracy of ±0.03 m³/m³ typical (±0.02 m³/m³ soil specific) plus the mote accuracy of ±0.001 m³/m³ at 25°C (77°F). There are additional temperature accuracy deviations of ±0.003 m³/m³ / °C maximum for the probe across operating temperature environment, typical <0.001 m³/m³ / °C. (The temperature dependence of the mote is negligible.)
Note 3: (RXW-SMC-xxx) Given the nature of the sensor design and sensor operating frequency, the system has inherent susceptibilities to Radio Frequency signals. The accuracy specification when subjected to certain RFI environments, such as those outlined in IEC 61000-4-3 and IEC 61000-4-6, is reduced to 0.061 m³/m³. The system level accuracy will be particularly affected when placed in an electric field of 3 V/m or greater in the 70 MHz range. RFI mitigation practices and physical deployment changes may reduce the systems susceptibility.
Note 4: (RXW-SMD-xxx) This is a system level accuracy specification and is comprised of the probe’s accuracy of ±0.03 m³/m³ typical (±0.02 m³/m³ soil specific) plus the mote accuracy of ±0.003 m³/m³ at 25°C (77°F). There are additional temperature accuracy deviations of ±0.003 m³/m³ / °C maximum for the probe across operating temperature environment, typical <0.001 m³/m³ / °C. (The temperature dependence of the mote is negligible.)
Note 5: (RXW-SMD-xxx): Given the nature of the sensor design and sensor operating frequency, the system has inherent susceptibilities to Radio Frequency signals. The accuracy specification when subjected to certain RFI environments, such as those outlined in IEC 61000-4-3 and IEC 61000-4-6, may be significantly reduced. The system level accuracy will be particularly affected when placed in an electric field of 3 V/m or greater in the 150 KHz to 1000 MHz range. RFI mitigation practices and physical deployment changes may reduce the systems susceptibility, however will yield reduced system accuracy. If deployments are planned in high RFI energy environments, Onset recommends on-site testing to determine system level accuracy.
Compatible items
Tripod Parts, Kits and Masts
Batteries
Grounding Wires
Compliance Certificates
Web-based Monitoring Systems - via remote communication
Communications
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