La CS616 mide el contenido volumétrico de agua desde el 0% hasta saturación. La sonda tiene una salida de señal en frecuencia de megahertz, fácilmente leible por nuestros dataloggers Campbell Scientific.Leer más
The CS616 is comprised of two 30-cm-long stainless steel rods connected to the measurement electronics. 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 CS616 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 CS616 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 CS616 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 CS616 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.
|Volumetric water content (VWC) of porous media (such as soil)
|0% to saturation
|Water Content Accuracy
|±2.5% VWC (using standard calibration with bulk EC of ≤ 0.5 dS m-1, bulk density of ≤ 1.55 g cm-3, and measurement range of 0% to 50% VWC)
|Long rods and lower frequency are well-suited for soft soil with low electrical conductivity (< 2 dS/m).
|Operating Temperature Range
|0° to +70°C
|±0.5% VWC in dry soil, ±1.5% VWC in typical saturated soil
|Better than 0.1% VWC
|±0.7 V square wave (with frequency dependent on water content)
|Power Supply Voltage
|5 Vdc minimum; 18 Vdc maximum
|4 Vdc minimum; 18 Vdc maximum
|CE compliant (Meets EN61326 requirements for protection against electrostatic discharge.)
|32 mm (1.3 in.)
|3.2 mm (0.13 in.)
|300 mm (11.8 in.)
|Probe Head Dimensions
|85 x 63 x 18 mm (3.3 x 2.5 x 0.7 in.)
|35 g per m (0.38 oz per ft)
|280 g (9.9 oz) without cable
Nota: lo siguiente muestra información de compatibilidad notable. No es una lista de todos los productos compatibles.
The RF emissions are below FCC and EU limits as specified in EN61326 if the CS616 is enabled less than 0.6 ms, and measurements are made less frequently than once a second. External RF sources can also affect the CS616 operation. Consequently, the CS616 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 was not used. It makes pilot holes into which the rods of the sensors can then be inserted. It replaces both the 14383 and 14384.
The reflectometer connects directly to one of the data logger’s single-ended analog inputs. A data logger control port is typically used to enable the CS616 for the amount of time required to make the measurement. Data logger instructions convert the probe square-wave output to period which is converted to volumetric water content using a calibration.
Número de FAQs relacionadas con CS616: 37
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If the CS615 rod length is reduced, the response of the probe to water content will change, and the recommended calibration is no longer valid. Additionally, reducing rod length will adversely affect the water content measurement resolution. However, the CS615 will respond in a similar manner to the response with standard length rods (30 cm). The response needs to be described for the modified probe to generate a calibration. CS615 water content resolution is better than 0.2% volumetric water content with 30 cm rods. If the rods are cut by 15 cm, water content resolution will be between 1% and 2%. A few additional points are:
The CS616 has a faster period output than the CS615-L, so it does not work with the 21X dataloggers.
If the electrical conductivity within the waste is less than 5 dS/m and there is good contact between the probe rods and the waste, the CS616/CS625 should respond predictably to changes in water content. The heterogeneous nature and changing bulk density of solid waste, however, make calibration difficult.
No. The output is too fast to be measured on the pulse channel of a 21X or CR7.
If a soil-specific calibration is performed, the CS616/CS625 may be used in soil with a maximum bulk electrical conductivity of 5 dS/m.
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.
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.
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.
Yes. For program examples and guidance on using a multiplexer with one of these reflectometers, see the CS616 and CS625 instruction manual.
Yes, but the CS616/CS625 will need a soil-specific calibration. The high organic matter content of peat will likely cause the CS616/CS625 period to be out of bounds for use with the CS616() CRBasic instruction and P138 Edlog instruction. In that situation, the CRBasic PeriodAvg() instructionor the Edlog P27 Period Average instruction may be used as described in the CS616 and CS625 instruction manual.