设计用于长期监测
概览
CS616测量从 0% 到水饱和的体积含水量。探头输出百万赫兹的振荡频率，按比例下降，容易被Campbell Scientific数据采集器所读取。
优势与特点
- Compatible with most Campbell Scientific data loggers
- High accuracy and high precision
- Fast response time
- Designed for long-term unattended water content monitoring
- Compatible with AM16/32-series multiplexers, allowing measurement of multiple sensors
- Probe rods can be inserted from the surface or buried at any orientation to the surface.
图像
技术说明
CS616含有连接到测量电子单元的2根30 cm长的不锈钢探针。电路板用环氧树脂封装，连接到电路板的4芯带屏蔽线缆给探头提供电源、激活测量以及监测输出信号。
CS616采用时域反射技术测量多孔介质（例如土壤）的体积含水量。类似TDR100的时域反射主机（测线器）对于CS616并不需要。CS616生成电磁脉冲，消逝行程时间和脉冲反射继而被测量，用于计算土壤体积含水量。
响应特征
沿CS616平行探针传输的信号被土壤溶液中的自由离子和土壤矿物成分的导电组分所消弱。在大多数应用中，该衰减并不足以影响CS616对土壤含水量变化的响应。CS616的响应曲线较好地被标准校准所描述。不过，在较大电导率的土壤、压实土、或较高粘土矿物含量的土壤中，应该特定土壤调整校准曲线。在CS616说明书提供了做这些校准调整的指导。
产品规格
| Measurements Made | Volumetric water content (VWC) of porous media (such as soil) |
| Measurement Range | 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) |
| Required Equipment | Measurement system |
| Soil Suitability | Long rods and lower frequency are well-suited for soft soil with low electrical conductivity (< 2 dS/m). |
| Rods | Not replaceable |
| Sensors | Not interchangeable |
| 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 | Better than 0.1% VWC |
| Resolution | 0.1% VWC |
| Output | ±0.7 V square wave (with frequency dependent on water content) |
| Current Drain |
|
| 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 |
兼容性
Please note: The following shows notable compatibility information. It is not a comprehensive list of all compatible products.
数据采集器
| Product | Compatible | Note |
|---|---|---|
| CR1000X | ||
| CR300 | ||
| CR3000 (retired) | ||
| CR310 | ||
| CR350 | ||
| CR6 | ||
| CR800 (retired) | ||
| CR850 (retired) |
Additional Compatibility Information
RF Considerations
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.
Installation Tool
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.
Data Logger Considerations
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.
相关技术文档
技术论文
常见问题解答
CS616: 36
展开全部收起全部
-
The CS616 has a faster period output than the CS615-L, so it does not work with the 21X dataloggers.
-
Running the cable through electrical conduit or PVC pipe will protect the cable from rodents. A trench 30 to 60 cm deep will protect it from most other human or animal activity. Some customers have found that extra cable can be coiled and left inside a box, such as an irrigation valve box or something similar. When using a box, seal any holes that are large enough for rodents to enter. When cables are exposed on the ground surface, some customers have found that wrapping the cables in the metal screening used for screen doors discourages animals from chewing on them.
-
No. The output is too fast to be measured on the pulse channel of a 21X or CR7.
-
The cable for the sensors is rugged and resistant to damage from the sun and typical weather conditions. However, it is susceptible to damage from rodents, machinery, shovels, and so forth. Running the cable through electrical conduit or PVC pipe will help protect it, but this is not an absolute requirement. In areas where rodent activity is low, direct burial in a trench is usually sufficient. A particularly vulnerable location is where the buried cables exit the ground and enter the enclosure housing the data logger. At that exit point, take steps to protect the cable from damage.
-
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.
-
Fine roots do not significantly affect the CS616/CS625 reading.
-
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 data logger. 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.
-
Campbell Scientific does not recommend splicing sensor cables. Sensors may be ordered with custom cable lengths, and Campbell Scientific recommends purchasing the correct length for the application. If the sensor cable needs to be lengthened, a junction box (if practical) is a more favorable option than a splice.
Note: A splice will void the sensor warranty, but a junction box does not modify the sensor and therefore does not void the warranty.
-
Yes, as long as the data logger can detect a ±700 mV square wave over a frequency range of 29 to 67 kHz.
-
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.
案例研究
Korea Expressway Corporation (KEC) was established in 1969 to construct and manage expressways throughout South......阅读更多
The Delaware Environmental Observing System (DEOS) is a real-time system dedicated to monitoring environmental conditions......阅读更多