CS655 是多參數(shù)智能傳感器，TDR時域反射法監(jiān)測土壤體積含水量、容積電導(dǎo)率和土壤溫度。它的信號輸出方式為SDI-12，可用于大多數(shù)的 Campbell Scientific 數(shù)據(jù)采集器。探針長度比CS650更短，可以監(jiān)測特高電導(dǎo)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(chǎn)品特點：
1.更大的采集體積，減少了誤差
2.對土壤質(zhì)地和電導(dǎo)率的影響進(jìn)行測量修正
3.估算很多種礦質(zhì)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(shù)、容積電導(dǎo)率（EC）和土壤溫度
技術(shù)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(huán)氧樹脂中，并將屏蔽電纜連接到電路板上用于數(shù)據(jù)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(dǎo)出介電常數(shù)、體積含水量和體積電導(dǎo)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(yīng)。 這種損失效應(yīng)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(jìn)行土壤特定的校準(zhǔn)。
通過衰減測量，計算了土壤的體積電導(dǎo)率。 熱敏電阻與靠近環(huán)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(zhǔn)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(jìn)入環(huán)氧體區(qū)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(dǎo)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(shù) | |||
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 | ||
