The STM Soil Tension Meter is a stand-alone logging instrument for the measurement of soil water potential.
The STM Soil Tension Meter can support up to 5 pressure transducers. ICT International supplies 3 different types of pressure transducers which can measure in the ranges: ±7 kPa, ±100 kPa or -100 to +200 kPa. Tensiometers include designs for soil columns and field sites.
The STM is a fully self-contained unit requiring power input from a 22W solar panel (field applications) or 24V power supply (laboratory applications). Communication is via a USB port or wireless connectivity. The STM is IP-65 rated and has a Windows and Mac compatible GUI for complete logging solutions including look-up tables, scripts and sensor calibration capabilities.
Applications:
The continuous measurement of soil water potential in the field, glasshouse or soil columns.
Specifications |
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Analogue Channels | 5 differential |
Resolution | 0.00001V—24-Bit |
Accuracy | 0.001V |
Minimum Logging Interval | 1 second |
Delayed Start | Suspend Logging, Customised Intervals |
Sampling Frequency | 10Hz |
Data |
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Communications | USB, Wireless Radio Frequency 2.4 GHz |
Data Storage | MicroSD Card, SD, SDHC & SDXC Compatible (FAT32 format) |
Software Compatibility | Windows 8, 8.1 & 10. Mac OS X |
Data Compatibility | FAT32 format for direct exchange of SD card with any PC |
Data File Format | Comma Separated Values (CSV) for compatibility with all software programs |
Memory Capacity | Up to 16GB, 4GB microSD card included. |
Operating Conditions |
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Temperature Range | -40°C to +80°C |
R/H Range | 0-100% |
Upgradeable | User Upgradeable firmware using USB boot strap loader function |
POWER |
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Internal Battery Specifications | |||
960mAh Lithium Polymer, 4.20 Volts fully charged | |||
External Power Requirements | |||
Bus Power | 8-30 Volts DC, non-polarised, current draw is 190mA maximum at 17 volts per logger | ||
USB Power | 5 Volts DC | ||
Internal Charge Rate | |||
Bus Power | 60mA – 200mA Variable internal charge rate, maximum charge rate of 200mA active when the external voltage rises above 16 Volts DC | ||
USB Power | 100mA fixed charge rate | ||
Internal Power Management | |||
Fully Charged Battery | 4.20 Volts | ||
Low Power Mode | 3.60 Volts – Instrument ceases to take measurements | ||
Discharged Battery | 2.90 Volts – Instrument automatically switches off at and below this voltage when no external power connected. | ||
Battery Life varies | |||
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