CS655 是多參數智能傳感器，TDR時域反射法監測土壤體積含水量、容積電導率和土壤溫度。它的信號輸出方式為SDI-12，可用于大多數的 Campbell Scientific 數據采集器。探針長度比CS650更短，可以監測特高電導率的土壤，適合使用在基巖類土壤中。如果采用到ET107蒸散站的話請選用CS655-LC。
產品特點：
1.更大的采集體積，減少了誤差
2.對土壤質地和電導率的影響進行測量修正
3.估算很多種礦質土類型土壤中的含水量
4.多功能的傳感器 — 可測量介電常數、容積電導率（EC）和土壤溫度
技術說明：
CS655由兩個12厘米長的不銹鋼棒連接到一個印刷電路板組成。電路板封裝在環氧樹脂中，并將屏蔽電纜連接到電路板上用于數據記錄器連接。
CS655測量信號傳播時間、信號衰減和溫度。 然后從這些原始值中導出介電常數、體積含水量和體積電導率。 測量的信號衰減被用來校正反射探測和傳播時間測量的損耗
效應。 這種損失效應校正允許在體積EC≤8ds m-1的土壤中精確測量水分含量，而無需進行土壤特定的校準。
通過衰減測量，計算了土壤的體積電導率。 熱敏電阻與靠近環氧樹脂表面的探針棒熱接觸，測量溫度。 水平安裝的傳感器提供了準確的土壤溫度用于計算測量在同一深度的土壤水含量。 如果采用其他方向安裝，所測量的溫度是靠近桿入口進入環氧體區域的溫度。
Measurements Made | Soil electrical conductivity (EC), relative dielectric permittivity, volumetric water content (VWC), soil temperature | ||
Required Equipment | Measurement system | ||
Soil Suitability | Short rods are easy to install in hard soil. Suitable for soils with higher electrical conductivity. | ||
Sensing Volume（探測體積） | 3600 cm3 (~7.5 cm radius around each probe rod and 4.5 cm beyond the end of the rods) | ||
Electromagnetic | CE compliant (Meets EN61326 requirements for protection against electrostatic discharge and surge.) | ||
Operating Temperature Range | -50° to +70°C | ||
Sensor Output | SDI-12; serial RS-232 | ||
Warm-up Time | 3 s | ||
Measurement Time | 3 ms to measure; 600 ms to complete SDI-12 command | ||
Power Supply Requirements | 6 to 18 Vdc (Must be able to supply 45 mA @ 12 Vdc.) | ||
Maximum Cable Length | 610 m (2000 ft) combined length for up to 25 sensors connected to the same data logger control port | ||
Rod Spacing | 32 mm (1.3 in.) | ||
Ingress Protection Rating | IP68 | ||
Rod Diameter | 3.2 mm (0.13 in.) | ||
Rod Length | 120 mm (4.7 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) | ||
Probe Weight | 240 g (8.5 oz) without cable | ||
Electrical Conductivity電導率 | |||
Range for Solution EC | 0 to 8 dS/m | ||
Range for Bulk EC | 0 to 8 dS/m | ||
Accuracy | ±(5% of reading + 0.05 dS/m) | ||
Precision | 0.5% of BEC | ||
Relative Dielectric Permittivity相對介電常數 | |||
Range | 1 to 81 | ||
Accuracy | · ±(3% of reading + 0.8) from 1 to 40 for solution EC ≤ 8 dS/m · ±2 (from 40 to 81 for solution EC ≤ 2.8 dS/m) | ||
Precision | < 0.02 | ||
Volumetric Water Content體積含水量 | |||
Range | 0 to 99% (with M4 command) | ||
Water Content Accuracy | · ±1% (with soil-specific calibration) where solution EC < 3 dS/m · ±3% (typical with factory VWC model) where solution EC < 10 dS/m | ||
Precision | < 0.05% | ||
Soil Temperature | |||
Range | -50° to +70°C | ||
Resolution | 0.001°C | ||
Accuracy | · ±0.1°C (for typical soil temperatures [0 to 40°C] when probe body is buried in soil) · ±0.5°C (for full temperature range) | ||
Precision | ±0.02°C | ||
