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Building Intelligence
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SMT-A2 - Wireless Data Acquisition Unit
The SMT-A2 is SMT's next generation wireless data acquisition unit built with the same high precision electronics and stable circuitry features as the WiDAQ but features integrated moisture, RH and temperature sensors as well as prolonged battery life and almost 10x the wireless communicaiton range.
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Overview
General Description
The SMT-A2 Wireless Data Acquisition unit is a high precision measurement device designed for distributed remote sensor data acquisition. The built-in 24-bit A/D converter and low noise high precision measurement circuitry facilitates data acquisition from a wide variety of sensors.
Integrated Moisture Content, RH and temperature sensors make the SMT-A2 suitable for building monitoring applications.
External sensor inputs, LCD display, large memory capacity and extended wireless range gives the SMT-A2 flexibility in a wide range of applications.
The SMT-A2 unit communicates wireless sensor readings to the SMT Building Intelligence gateway. Optional powered repeaters can be used to extend the wireless range.
Applications
- Remote sensor analysis and data collection
- High precision data acquisition
- Building science research
- Targeted repair monitoring
- Restoration monitoring
Features
- Integrated moisture content sensing elements.
- Integrated relative humidity and temperature sensors.
- Two external resistance channels capable of reading wide moisture content ranges and precision thermistors.
- Sensor inputs use compact audio jacks for quick and simple connectivity.
- Internal memory capable of logging 340,000 data points.
- Auxiliary input for voltage measurement capable of reading 0-5V sensors.
- Wireless transceiver with 1000m line of sight communication.
- Communicates to SMT Building Intelligence Gateway (BiG) via USB to Wireless device; SMT-I2.
- Extreme low power device suitable for long term battery operation.
- USB connectivity supports data downloads and firmware upgrades.
- Backlit LCD user interface for easy network and sensor verification
- Rechargeable batteries via USB port.
Specs
Electrical
| Wireless | |
| Specification | IEEE 802.15.4 |
| Max Distance from coordinator | 1000m line of site. Powered repeaters can be added to extend range. |
| Max Nodes per coordinator | 32 (dependent on application density and acquisition speed) |
| Battery | |
| Life | 1000 hours (dependent on sample frequency) |
| Battery | |
| Type | Ni-MH Rechargeable Eneloop HR-4UTGA |
| Voltage | 1.2V |
| Capacity | Typical: 800 mAh Minimum 750 mAh |
| Self Discharge | 75% after 3 years |
| Charging Cycles | Up to 1500 |
| Charger | USB 5V |
| Memory and USB | |
| Memory | 16 Mbit EEPROM for data storage Stores 340,000 samples. |
| USB | USB 1.0 Interface |
Environmental
| Operating Temperature | 0° to 40°C / 32° to 104°F |
| Storage Temperature | -25° to 70°C / -13° to 158°F |
| Humidity | 5% to 100% RH non-condensing |
| Electrostatic Discharge (ESD) | 8kVdc air, 4 kVDC contact (exposed inputs) |
Safety/Regulatory
| Safety Requirements | SELV Separated Extra Low Voltage |
| Regulatory | Contains FCC ID: OA3MRF24J40MA This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. |
Measurement
| Internal Temperature | |
| Sensor | Cantherm MF58104F3950 Beta 4390K |
| Range | -40°C to +70°C |
| Resolution | 0.1°C |
| Accurac | ±1°C |
| Internal Relative Humidity | |
| Sensor | Honeywell HCH-1000-001 |
| Accuracy Range | 10-95% RH |
| Resolution | ±0.5% |
| Accuracy | ±5% |
| Resistance | |
| Range Resolution Accuracy |
10Ω to 100Ω 1Ω ±5% |
| Range Resolution Accuracy |
100Ω to 100KΩ 10Ω ±1% |
| Range Resolution Accuracy |
100KΩ to 1GΩ 1KΩ ±5% |
Mounting
The SMT-A2 can be housed in a mobile unit used for indoor applications, sealed in an IP67 enclosure or mounted on a double gang face plate.
Consult Application Notes and specific installation instructions for further details.
Connectivity
External Port Connectivity
Resistance based and voltage based sensors can be
connected to the external audio jack ports:
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Resistance Based Sensors Plug resistance based sensors into the blue audio jack port (input 1/2) |
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0-5V Sensors Plug 0-5V Sensors into the white audio jack port. (input 3/4) Thermistor or short must be connected between C and D to signal port is active. |
Screenshots
Main Menu
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The main menu contains links to the submenus as shown below. The header reports the immediate status of the unit. |
Network Status
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To join the network ensure BiG is running with an SMT-I2 USB to Wireless interface and select Network.
Joining network will be displayed, if joining was successful Joining Network on 25 will be displayed where 25 is the wireless channel, otherwise No Network will be displayed. To rejoin the network select Join. To see the status of the network select Info from the main menu. |
Measure Display - Restoration:
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Values are converted to moisture content, temperature and relative humidity. The associated temperature sensor used for temperature compensation is displayed next to each reading. |
Measure Display - Research:
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Resistance is in ohms and voltage in volts. Range will be adjusted automatically. Full values will be transmitted and stored in BiG. |
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SMT Research, LTD. | 200-75 W Broadway | Vancouver, BC | V5Y 1P1