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.
The continuous measurement of soil water potential in the field, glasshouse or soil columns.
|Analogue Channels||5 differential|
|Minimum Logging Interval||1 second|
|Delayed Start||Suspend Logging, Customised Intervals|
|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.|
|Temperature Range||-40°C to +80°C|
|Upgradeable||User Upgradeable firmware using USB boot strap loader function|
|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|