WP4 & WP4-T Dewpoint Meters
Measuring water potential using a pressure plate or filter paper is imprecise and can take several weeks. The WP4 and WP4-T measure water potential in less than 5 minutes from 0 to -300 MPa with a resolution of 0.1 MPa. Using the AOAC-approved Chilled Mirror Dewpoint Technique, the WP4 measures water potential by determining the relative humidity of the air above the sample in a closed chamber (at temperature equilibrium, relative humidity is a direct measurement of water potential). The instrument is easy to use and maintain, and calibration is simple.
WP4-T with Internal Temperature Control:
The WP4-T features internal temperature control. Water potential mesurements are temperature sensitive: if the lab temperature
fluctuates ±5°C, water potential readings can vary as much as ±0.5 MPa. The WP4-T enables you to eliminate the
effect of ambient temperature fluctuations.
Other applications of internal temperature control:
- To study effects of temperature on water potential.
- Sample-to-sample comparison of water potential independent of temperature.
Features:
The WP4 is a bench-top enclosure with an integral sensor drawer. To initiate a reading, simply close the sample drawer. You can
transfer your soil suction data to a computer or printer with the included serial RS232 interface cable. Additional features
include:
- Easy-to-clean, durable one-piece sensor.
- Push-button calibration using performance verification standards.
- Continuous measurement mode (for time-dependent studies or samples with low water emission).
- Intelligent error messages to keep you informed of instrument performance.
Benefits:
- Unparalleled accuracy.
- Speed: 5 minutes per sample.
- 1 year warranty on parts and labor.
- Auto-ranging: Up to 50% faster speed at all soil suction levels.
- No tool maintenance: Thumb-screws secure lid and sensor plate.
Each WP4 and WP4-T is shipped with:
User manual, cleaning kit, 12 KCl verification standards, 100 sample cups and lids, an RS232 serial cable, and a power cord.