PSY1 Leaf Psychrometer
The leaf psychrometer follows the same principle of measurement as the stem psychrometer, however the body of the chamber is reduced to accommodate smaller and thinner leaf areas in several plant species. The technique used to prepare and install this instrument has also changed as it requires additional care to prepare the installation site. The leaf psychrometer measures the water potential (water status) on a leaf of a plant. The leaf water potential is a quantified indicator of how water stressed a particular plant is based on the measurement taken from the leaf.
In terms of data logging capabilities of the PSY1, they all remain the same regardless of the application (Leaf or Stem psychrometer chambers). The difference between a leaf and stem psychrometer chamber is the size and plant preparation.
See Full Playlist of PSY1 Psychrometer Youtube Videos Here
Introduction Videos
PSY1 Psychrometer Theory of Operation:
PSY1 Psychrometer Principle of Operation:
Professor Mike Dixon: In Situ Stem Psychrometer, Part A:
Professor Mike Dixon: In Situ Stem Psychrometer, Part B:
Installation Videos
PSY1 Psychrometer Installation:
PSY1 Psychrometer Installation Preparation Video
PSY1 Psychrometer Installation Issues Video
PSY1 Psychrometer De-Installation Video
PSY1 Psychrometer Adjustment Video
Calibration Videos
PSY1 Psychrometer Calibration Procedure:
PSY1 Psychrometer Calibration Sealant Video
PSY1 Psychrometer Calibration Solutions Video
PSY1 Psychrometer Calibration Equipment Video
Cleaning Videos
PSY1 Psychrometer Cleaning With Chloroform:
PSY1 Psychrometer Cleaning With Electronic Contact Cleaner Video
Diagnostics Video
PSY1 Psychrometer Diagnostics:
Figure 1 – The leaf water potential (MPa) of a pepper plant was monitored by a psychrometer continuously at a 10 minute measurement interval.
Figure 2 – The diurnal plant water status of a pepper plant was measured by leaf psychrometer, represented by the green line. Measurements were monitored every 10 minutes continuously for a two week period. Irrigation events were represented by the dashed blue lines and occurred on the 4th, 7th, 8th and 14th August 2016 at 19:15, 15:49, 19:40, and 14:30, respectively.
Figure 3 – Poplar tree instrumented with psychrometers (stem and leaf) and a sap flow meter on the main stem.
Figure 4 – Diurnal time course showing the plant water status (psychrometers) of both the stem and leaf with concurrent sap flow measurements over a 4-day period. Measurements were collected every 10 minutes with PSY1 and SFM data logging systems. The red line represents the heat pulse velocity (cm/hr), blue line represents the water status on the stem, and the green line represents the water status of the poplar tree.
SPECIFICATIONS FOR THE PSYCHROMETER |
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| 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, 4GB 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: 19mm Depth: 19mm Depth with calibration chamber: 27mm Weight with cable: 120g |
| Leaf Clamp | Clamp length with Aluminium Rod: 140mm Clamp length: 30mm Clamp width: 21mm Clamp depth: 25mm Weight of Clamp: 26g Weight of Clamp with Aluminium Rod: 50g |
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, 4GB MicroSD card included. |
Operating Conditions |
|
| Temperature Range | -40°C to +80°C |
| R/H Range | 0-100% |
| Upgradable | 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 | |
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PSY-SLC
Small Leaf Clamp for the PSY1 Leaf Psychrometer.