Stem Psychrometer
The PSY1 Stem Psychrometer is a very powerful tool integrating all the ambient environmental parameters acting upon the plant such as solar radiation, temperature, humidity, wind speed and water availability into a single continuously measurable variable.
The PSY1 is a stand-alone instrument for the measurement of stem water potential. It can continuously log changes in plant water status/potential, which directly reflect the energy required to access water or the stress the plant is under.
| SPECIFICATIONS FOR THE PSYCHROMETER | |
| Units | MPa |
| Range | -0.1 MPa to -10 Mpa (1 to 100 Bars) |
| Resolution | 0.01 MPa (0.1 Bar) |
| Accuracy | ±0.1 MPa (1 Bar) |
| Response Time | Measurement mode: 51 seconds Live mode: 1 second |
| Sampling Rate | 10 Hz |
| DATA | |
| Computer Interface | USB, Wireless RF 2.4 GHz |
| Data Storage | MicroSD Card |
| Memory Capacity | Up to 16GB, 8GB MicroSD card included. |
| OPERATING CONDITIONS | |
| Temperature Range | -10 to 50°C |
| R/H Range | 0-99% |
| DIMENSIONS | |
| Logger | Length: 170 mm Width: 80 mm Depth: 35 mm |
| Psychrometer Chamber | Diameter: 25.5mm Depth: 20mm Depth with calibration chamber: 30mm |
| SPECIFICATIONS FOR THE METER | |
| INSTRUMENT LOGGING | |
| Analogue Channels | 1x Input, (1x Sensor) High precision 24bit ADC circuit 1x Output – PSY Chamber Heater Circuit |
| Minimum Logging Interval | 1 second |
| Delayed Start | Suspend Logging, Customised Intervals |
| Sampling Frequency | 10Hz |
| DATA | |
| 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 and Mac |
| Data Compatibility | FAT32 compatible for direct exchange of SD card with any Windows PC and Mac |
| Data File Format | Comma Separated Values (CSV) for compatibility with all software programs |
| Memory Capacity | Up to 16GB, 8GB MicroSD card included. |
| OPERATING CONDITIONS | |
| Temperature Range | -10°C to +50°C |
| R/H Range | 0-100% |
| Upgradable | User Upgradeable firmware using USB boot strap loader function |
| POWER | |
| Internal Battery Specifications | |
| 950mAh 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 | |
| With a recommended power source connected, operation can be continuous.3 days at hourly logging interval without chamber heating1 day with chamber heating |
