This product is no longer available. Some accessories, replacement parts, or services may still be available.
| Services Available | |
|---|---|
| Repair | No |
| Calibration | No |
| Free Support | No |
Overview
The 227, manufactured by Delmhorst, is a cylindrical gypsum block that estimates soil water potential from -10 to -1000 kPa. It connects directly to a datalogger.
Read MoreBenefits and Features
- Compatible with most Campbell Scientific data loggers
- Contains blocking capacitors in its cable that minimize galvanic degradation and measurement errors due to ground loops
- Measures wide range of matric potential
- Buffers salts in soil
- No maintenance required
Images
Detailed Description
The 227 determines soil water potential by measuring electrical resistance. When the 227 is wet, electrical resistance is low. As the 227 dries, resistance increases.
The 227 cylindrical block is composed of gypsum cast around two concentric electrodes, which confine current flow to the interior of the block, greatly reducing potential ground loops. Gypsum located between the outer electrode and the soil creates a buffer against salts that may affect the electrical conductivity.
Campbell Scientific recommends removing the 227 during winter.
Specifications
| Material | Gypsum |
| Measurement Range | -10 to -1000 kPa |
| Calibration | Individual calibrations are required for accurate measurements. Refer to the sensor manual for more information. |
| Operating Temperature | Soil temperatures above freezing |
| Life Expectancy | Two freeze-thaw cycles |
| Electrode Description | Concentric cylinders |
| Center Electrode | Excitation |
| Outer Electrode | Ground |
| Cylinder Diameter | ~2.25 cm (0.88 in.) |
| Cylinder Length | ~2.86 cm (1.25 in.) |
| Weight | 180 g (0.4 lb) |
Compatibility
Please note: The following shows notable compatibility information. It is not a comprehensive list of all compatible products.
Dataloggers
| Product | Compatible | Note |
|---|---|---|
| 21X (retired) | ||
| CR10 (retired) | ||
| CR1000 (retired) | ||
| CR10X (retired) | ||
| CR200X (retired) | ||
| CR206X (retired) | ||
| CR211X (retired) | ||
| CR216X (retired) | ||
| CR23X (retired) | ||
| CR295X (retired) | ||
| CR3000 (retired) | ||
| CR500 (retired) | ||
| CR5000 (retired) | ||
| CR510 (retired) | ||
| CR800 (retired) | ||
| CR850 (retired) | ||
| CR9000 (retired) | ||
| CR9000X (retired) |
Additional Compatibility Information
Data Logger Considerations
Two single-ended channels and one excitation channel per probe are required.