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Der CS625 misst den volumetrischen Wassergehalt von 0% bis zur Sättigung. Er ist sehr ähnlich dem CS616, aber speziell für den Einsatz mit dem CR200 und CR200X modifiziert. Der Sensor gibt die Frequenz einer 0-3,3V -Rechteckwelle aus und kann damit vom CR200(X) abgefragt werden.
Lesen Sie mehrThe CS625 consists of two 30-cm-long stainless steel rods connected to a printed circuit board. The circuit board is encapsulated in epoxy, and a shielded four-conductor cable is connected to the circuit board to supply power, enable probe, and monitor the output.
The CS625 measures the volumetric water content of porous media (such as soil) using the time-domain measurement method; a reflectometer (cable tester) such as the TDR100 is not required. This method consists of the CS625 generating an electromagnetic pulse. The elapsed travel time and pulse reflection are then measured and used to calculate soil volumetric water content.
The signal propagating along the parallel rods of the CS625 is attenuated by free ions in the soil solution and conductive constituents of the soil mineral fraction. In most applications, the attenuation is not enough to affect the CS625 response to changing water content, and the response is well described by the standard calibration. However, in soil with relatively high soil electrical conductivity levels, compacted soils, or soils with high clay content, the calibration should be adjusted for the specific medium. Guidance for making these adjustments is provided in the operating manual.
Operating Temperature Range | 0° to 70°C |
Probe-to-Probe Variability | ±0.5% VWC in dry soil, ±1.5% VWC in typical saturated soil |
Precision | 0.1% VWC |
Resolution | 0.1% VWC |
Output | 0 to 3.3 V square wave (with frequency dependent on water content) |
Current Drain | 65 mA @ 12 Vdc (when enabled) |
Power Supply Voltage | 5 Vdc minimum; 18 Vdc maximum |
Enable Voltage | 4 Vdc minimum; 18 Vdc maximum |
Electromagnetic | CE compliant (Meets EN61326 requirements for protection against electrostatic discharge.) |
Rod Spacing | 32 mm (1.3 in.) |
Rod Diameter | 3.2 mm (0.13 in.) |
Rod Length | 300 mm (11.8 in.) |
Probe Head Dimensions | 85 x 63 x 18 mm (3.3 x 2.5 x 0.7 in.) |
Cable Weight | 35 g per m (0.38 oz per ft) |
Weight | 280 g (9.9 oz) without cable |
Please note: The following shows notable compatibility information. It is not a comprehensive list of all compatible products.
Product | Compatible | Note |
---|---|---|
CR1000 (retired) | ||
CR200X (retired) | ||
CR216X (retired) | ||
CR300 (retired) | ||
CR3000 | ||
CR310 | ||
CR5000 (retired) | ||
CR800 (retired) | ||
CR850 (retired) | ||
CR9000X (retired) |
The RF emissions are below FCC and EU limits as specified in EN61326 if the CS625 is enabled less than 0.6 ms, and measurements are made less frequently than once a second. External RF sources can also affect the CS625 operation. Consequently, the CS625 should be located away from significant sources of RF such as ac power lines and motors.
The CS650G makes inserting soil-water sensors easier in dense or rocky soils. This tool can be hammered into the soil with force that might damage the sensor if the CS650G were not used. It makes pilot holes into which the rods of the sensors can then be inserted. It replaces both the 14383 and 14384.
Each CS625 requires a single-ended input channel. A control port is used to enable one or more probes.
Note: A maximum of four CS625 probes can be measured by one CR200(X) datalogger. Valid channel options are analog channels 1 through 4.
Number of FAQs related to CS625: 34
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300 m (1,000 ft).
Yes, as long as the datalogger can detect a 0 to 3300 mV square wave over a frequency range of 29 to 67 kHz.
The CS616/CS625 will survive frozen soil conditions, but the principle behind using bulk soil dielectric permittivity to estimate water content requires that the water be in liquid form. When soil water freezes, its dielectric drops from approximately 80 to 4, making it indistinguishable from soil solids. Consequently, the CS616/CS625 is not able to measure the water content of frozen soil.
The period value is corrected to the temperature at which the water content calibration was performed, and then the water content equation is applied to the corrected period. Temperature correction is soil specific because the effect that temperature has on the period value varies with soil texture and electrical conductivity. A temperature correction equation that was developed for a sandy loam soil with low bulk electrical conductivity is provided in the CS616 and CS625 instruction manual.
No. The output is too fast to be measured on the pulse channel of a 21X or CR7.
No. Although the CS616/CS625 could be calibrated to convert its period reading to the dielectric permittivity of snow, there is not an easy way to relate the permittivity to liquid water content. This is because the density of snow changes over time and the amount of liquid water that can be held in the solid matrix is relatively small. Additionally, the sensor emits infrared radiation that melts snow away from its rods, similar to the way snow melts around the base of a tree.
The CS616 and CS625 are not appropriate sensors for this application because of the lack of good contact between the rods and the snow, as well as the dynamic nature of the solid matrix.
Some customers have tried to use the CS616 or CS625 to measure the moisture content within a tree, but the calibration proved to be problematic. Campbell Scientific cannot provide any specific guidance for this application.
The CS616 and CS625 are water-content reflectometers with measurement electronics built into the probe head. The electronics generate a signal, which is sent directly to the datalogger. The CS610-L, and other three-rod probes sold by Campbell Scientific, are TDR probes that have no electronic components and serve as wave guides for a time-domain reflectometer such as the TDR100.
The CS616/CS625 can measure volumetric water content over the entire range from completely dry to saturation. A soil-specific calibration will improve accuracy, especially in very dry soil.
If the new site has soil with a different soil type, a soil-specific calibration may be needed. For soil that is sandy or sandy loam with low bulk electrical conductivity, the calibration equation in the CS616 and CS625 instruction manual works well.