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.
Soil column testing
Moisture retention curves
Soil water potential for irrigation monitoring
The continuous measurement of soil water potential in the field, glasshouse or soil columns.
Precise measurements of soil matric potential
Live monitoring of sorption and desorption curves
Up to 5 sensor capacity
Minimum Logging Interval
Suspend Logging, Customised Intervals
USB, Wireless Radio Frequency 2.4 GHz
MicroSD Card, SD, SDHC & SDXC Compatible (FAT32 format)
Windows 7, 8, 8.1 & 10. Mac OS X
FAT32 format for direct exchange of SD card with any PC
Data File Format
Comma Separated Values (CSV) for compatibility with all software programs
Up to 16GB, 4GB microSD card included.
-40°C to +80°C
User Upgradeable firmware using USB boot strap loader function
Internal Battery Specifications
960mAh Lithium Polymer, 4.20 Volts fully charged
External Power Requirements
8-30 Volts DC, non-polarised, current draw is 190mA maximum at 17 volts per logger
5 Volts DC
Internal Charge Rate
60mA – 200mA Variable internal charge rate, maximum charge rate of 200mA active when the external voltage rises above 16 Volts DC
100mA fixed charge rate
Internal Power Management
Fully Charged Battery
Low Power Mode
3.60 Volts – Instrument ceases to take measurements
2.90 Volts – Instrument automatically switches off at and below this voltage when no external power connected.
Battery Life varies
Example A: With a recommended solar panel and/or recommended power source connected, operation can be continuous.
Example B: Power consumption is dependent on number and type of sensors connected, frequency of measurement and measurement duration.