HFP01SC 测量土壤热通量,通常用于能量平衡系统或波文比通量系统。倾向用于那些要求最高可能测量精度的应用。每个站点至少需要2个土壤热通量传感器,才能提供足够的空间平均。带有非均匀介质的站点可能需要更多的传感器。
HFP01SC 包含一个热电堆和一个薄膜加热器。热电堆来测量通过传感器板上的温度梯度。在原位野外校准期间,加热器生成通过传感器板的热通量,其功率大小由数据采集器测量;数据采集器同时测量传感器的响应信号,再计算生成新的校准常数。出厂时,每一个热通量板传感器都会单独校准,输出热通量。
自校准修正了由传感器与周围介质之间热传导率的差异、温度变化以及轻微的传感器不稳定性等因素所导致的误差。
Sensor Type | Thermopile with film heater |
Sensitivity | 50 μV W-1 m-2 (nominal) |
Nominal Resistance | 2 Ω |
Temperature Range | -30° to +70°C |
Expected Typical Accuracy | ±3% of reading |
Heater Resistance | 100 Ω (nominal) |
Heater Voltage Input | 9 to 15 Vdc |
Heater Voltage Output | 0 to 2 Vdc |
Duration of Calibration | ±3 minutes @ 1.5 W (typically performed every 3 to 6 hours) |
Average Power Consumption | 0.02 to 0.04 W |
Plate Diameter | 80 mm (3.15 in.) |
Plate Thickness | 5 mm (0.20 in.) |
Weight | 200 g (7.05 oz) without cable |
CR1000X program that measures the HFP01SC, performs the self-calibration, and checks for calibration validity. Refer to the manual for the equations used for the self-calibration and calibration-validity checks. A table in the manual provides a cross reference of the terms in the equations in the manual with the constants and variables in the example data logger program.
HFP01SC-L: 13
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Rather than using a running average to find the millivolt output during a calibration, use a single sample with 50 or 60 Hz integration. See Example 1 in the 2014 or later version of the HFP01SC-L manual.
No. The HFP01SC-L must be in full contact with the media. Railroad ballast is too coarse.
The example CRBasic program runs in either SequentialMode or PipeLineMode. To force the CRBasic program to run in PipeLineMode, add the instruction PipeLineMode to the beginning of the program.
A calibration shift occurs if the HFP01SC-L is not making full contact with the soil during the calibration cycle. The following could cause the plate to lose contact with the soil: a soil freeze/thaw cycle, soil swelling/contracting because of extreme drying/wetting cycles, or rodents burrowing past the plate.
The in-situ calibration is helpful for quality assurance/quality control. The multiplier determined from the in-situ calibration should be within ±10% of the factory-determined calibration. If it is not, the plate may be damaged, not wired correctly to the data logger, or not making full contact with the soil.
The information included on a calibration sheet differs with each sensor. For some sensors, the sheet contains coefficients necessary to program a data logger. For other sensors, the calibration sheet is a pass/fail report.
This depends on the information contained in the calibration sheet:
大多数 Campbell Scientific 传感器的型号中都带有 –L,它表示用户指定线缆长度。如果传感器型号名称列有 –LX (这里 “X” 是其它的某个字符), 那么该传感器需要用户指定长度,但线缆尾端会配有用于某个独特系统的特殊快速接头:
如果一个传感器的主型号数字的后面没有被指定 –L 或其它的 –LX 字符,那么该传感器将具有固定的线缆长度。在产品页面订购栏中 (Ordering tab) 的描述字段的末尾,会列出线缆的长度。例如 034B-ET 型号的描述字段含有信息:Met One风传感器适用于ET气象站,67英寸线缆 (Met One Wind Set for ET Station, 67 inch Cable)。产品按固定的线缆长度做尾端处理,默认是尾线方式。
如果线缆尾端配有用于某个独特系统的特殊快速接头,则型号尾部的字符会指定该传感器用于哪一个系统。例如,034B-ET 型号表明该传感器是一个 034B 且用于 ET107 系统。
不是每一种传感器都有不同的线缆尾端选项。通过查找传感器产品页面的订购栏 (Ordering tab) 中的两个位置,可以检查某种特定传感器的可用的线缆尾端选项:
如果传感器以 –ET, –ETM, –LC, –LQ, 或 –QD 等版本的型号供应,那么线缆尾端选项已经反映在该传感器的产品型号中。例如,034B 以 034B-ET, 034B-ETM, 034B-LC, 034B-LQ, 和 034B-QD 等型号供应。
所有其它的线缆尾端选项,如果可用,会列在该传感器产品页面的订购栏 (Ordering tab) 中的线缆尾端选项 (“Cable Termination Options) 区域。例如,034B-L 风速风向传感器具有 –CWS, –PT, 和 –PW 等线缆尾端选项,显示在 034B-L 产品页面的 订购栏 (Ordering tab) 位置。
注: 当更新的产品添加到我们的库存中时,一般来说,我们会在单个传感器的产品型号下面列出多种线缆尾端选项,而不是创建多个产品型号。例如,HC2S3-L 具有 –C 线缆尾端选项用于连接到 CS110,而我们并没有使用 HC2S3-LC 产品型号。