CS215采用Sensirion SHT75型组合式相对湿度和温度元件，来提供精确而稳定的测量。Sensirion SHT75元件可在野外更换，消除了由重校准产生的下线时间。CS215输出SDI-12信号，可由大多数Campbell Scientific数据采集器来测量。
|Sensing Element||Sensirion SHT75|
|Measurement Description||Temperature, relative humidity|
|Communication Standard||SDI-12 V1.3 (responds to a subset of commands)|
|Housing Material||Anodized aluminum|
|Housing Classification||IP65 (NEMA 4)|
|Sensor Protection||Outer glass-filled polypropylene cap. Inner expanded PTFE filter. Filter material has a porosity of 64% and a pore size of < 3μm.|
|Typical Current Drain||
|EMC Compliance||Tested and conforms to IEC61326:2002.|
|Operating Temperature Range||-40° to +70°C|
|Field Replaceable Chip or Recalibrate||Field-replaceable chip|
|Length||18.0 cm (7.1 in.) including strain relief|
|Weight||150 g (5.3 oz) with 3.05 m (10 ft) cable|
|Measurement Range||0 to 100% RH (-20° to +60°C)|
|Output Resolution||0.03% RH|
|Short-Term Hysteresis||< 1% RH|
|Temperature Dependence||Better than ±2% (-20° to +60°C)|
|Typical Stability||±1.0% per year|
|Response Time with Filter||< 20 s (63% response time in still air)|
|Calibration Traceability||NIST and NPL standards|
|Measurement Range||-40° to +70°C|
|Response Time with Filter||< 120 s (63% response time in air moving at 1 m s-1)|
Please note: The following shows notable compatibility information. It is not a comprehensive list of all compatible products.
When exposed to sunlight, the CS215 must be housed in a 41303-5A radiation shield. To attach the 41303-5A to a CM202, CM204, or CM206 crossarm, place the 41303-5A’s U-bolt in the bottom holes. To attach the radiation shield directly to a tripod mast, tower mast, or tower leg, place the U-bolt in the side holes.
The CS215-L Temperature and RH sensor can also be housed in the 43502 if a special adapter from R. M. Young (R. M. Young pn 43537) is used.
If the values are not within the published range of the sensor, there are several things to check:
Relative humidity (RH) from the probe is capped at 100%. If readings of 100% occur during drier conditions, it is possible that the chip, the entire sensor, or both have associated issues. Repair, maintenance, or replacement is likely needed. Contact Campbell Scientific for assistance.
Yes. This can be purchased from Campbell Scientific (pn 18144, Replacement RH and Temperature Element and Filter Cap for CS215). This chip replaces both the temperature and RH humidity sensing element.
Yes. This is pn 18142.
If the -100 is actually -99.999 for both temperature and RH, this is an indication of what should be a rare condition. This indicates that the microprocessor in the body of the probe cannot communicate with the sensor element correctly. To be more specific, the communication between the microprocessor and the sensor element includes a CRC check. The microprocessor tries up to three times to get data with a good CRC. If it does not succeed, its sets both values to -99.999.
The following are some reasons why this might happen, as well as some suggested solutions:
No. The sensor cannot be calibrated, but Campbell Scientific can perform a calibration verification that includes multiple points (temperature and relative humidity). Campbell Scientific recommends using three points for RH (10%, 50%, and 90%) at one temperature (25 degrees Celsius), as well as an additional temperature point. This verification process has an initial setup charge and an additional per-point charge. Campbell Scientific sends a document indicating the values tested to with the accompanying measurement from the associated sensor.
Yes, using pn 18144, Replacement RH and Temperature Element and Filter Cap for CS215. However, Campbell Scientific recommends taking the necessary precautions associated with changing electronics in the field. As this is a relatively small chip, it is not recommended to replace the chip during stormy weather or without having some type of collection container placed underneath in case the chip is accidentally dropped.
For assistance replacing the chip, refer to the “Maintenance and Calibration” section of the instruction manual.
The most significant difference is that the CS215-L has an SDI-12 output and that the HMP60-L has a voltage output. Additional differences are outlined in the “Air Temperature & Relative Humidity” brochure, which compares all of the Campbell Scientific temperature and relative humidity sensors.
Note the difference between calibration and a field check. Calibration cannot be done in the field, as it requires an experienced technician and specialized equipment.
Field checks of measurements can be done to determine if the data make sense with the real-world conditions. Follow these steps to field check a sensor: