The CS241 is the next generation of Campbell Scientific back-of-module temperature sensors with new features designed for bifacial photovoltaic (PV) module performance assessment and soiling. New improvements include a redesign of the probe head for easier installation, as well as better measurement performance with a smaller footprint optimized to reduce back-of-module shading and eliminate surface cooling. Other improvements include greater sensor-to-module bonding/adhesion and a thinner Teflon cable with a higher temperature rating. Lastly, to meet the requirements of performance validation, every CS241 is supplied with a NIST-traceable, serialized calibration certificate.
The CS241 provides PV stakeholders with the most accurate back-of-module temperature, even at long cable lengths, for use in power assessment and soiling of solar PV modules. Back-of-module temperature is critical for the evaluation of effective irradiance, soiling, and power conversion, making the sensor that can collect this data a vital part of any PV performance monitoring system.
The CS241 consists of a PT-1000 class A platinum resistance thermometer (PRT) encased in a specially designed slim-profile, low-mass aluminum disk. The slim design minimizes sensor impact on bifaciality with less than 2% area coverage on a full-sized cell. The disk shields the PRT from rapid temperature fluctuations while protecting the fragile PRT element during installation. It minimizes heat transfer, which eliminates surface cooling and results in the highest efficiency in measuring true temperature of the solar module. The adhesive of the disk has excellent thermal properties including a thermal conductance greater than 600 W/(m2*K), and it is extremely strong. This eliminates the need for high-temperature epoxy or tape for maximum sensor-to-module bonding, making the installation much easier.
The CS241 cable has been upgraded to a thin polytetrafluoroethylene (PTFE) Teflon-jacketed cable. This has two distinct advantages:
Combining the highest-quality components and thoughtful, coherent CS241 sensor design results in the highest back-of-module temperature-sensor performance. The CS241 sensor meets or exceeds the thermal properties, accuracy and uncertainty specifications defined by IEC 61724 for Class A performance and is compliant with IEC 60751, DIN EN 60751 (according to IEC 751).
Every CS241 includes a NIST-traceable, serialized calibration; alcohol swab; and zip ties that clip to the edge of a module frame.
|Sensor||Precision 1000 ohm Class A platinum sensing element (PT-1000)|
|Operating Temperature Range||-40° to +150°C|
|Class A PRT Accuracy||±(0.15 + 0.002t)°C|
|Temperature Coefficient||TCR = 3850 ppm/K|
|Long-Term Stability||Maximum Ro drift 0.04% (after 1000 h at 400°C)|
|Measuring Current||0.1 to 0.3 mA|
|Uncertainty||The temperature uncertainty is ±0.3° to 0.4°C in the measurement range of -40° to +100°C when measured using the CR1000X Measurement and Control Datalogger.|
|Disk Material||Anodized aluminum|
|Disk Diameter||2.54 cm (1.0 in.)|
|Height||0.419 cm (0.165 in.)|
|Weight||~27 g (0.06 lb) with connector and 1 m (3 ft) cable|
|Jacket Material||White semi-gloss PFA|
|Cable Diameter||0.216 cm (0.085 in.)|
|Cable Length||0.9144 m (3 ft)|
|Jacket Material||Black semi-gloss PVC, UL VW-1 sunlight resistant for outdoor use|
|UL||AWM 10012 1000V 105°C|
|Cable Diameter||0.622 cm (0.245 in.)|
|-NOTE-||Compliance information can be found in the Documents section of the web page.|
|Approvals||UL AWM 2586 1000V 105°C; CSA AWM 600V 105°C FT1|
|EMC Compliance||Conforms with Electromagnetic Compatibility Directive (EMC).|
|RoHS2||Conforms with the Restriction of Hazardous Substances Directive (RoHS2).|
|Industry Approvals||Compliant with IEC 60751, DIN EN 60751, Industrial Design (IEC Class 4) (according to IEC 751)|
|IP Rating||IP68 rating (self certified): 1 m submersion for 90 min|
Campbell Scientific recommends using the CS241 at the back of the bifacial module. Front-of-module temperature is not recommended because the temperature sensor itself will heat with direct exposure to the sun and thus not be at the same temperature as the module. Also, considering effective irradiance, front-of-module installation would block more effective irradiance from hitting the photovoltaic (PV) module and potentially negatively impact the module’s performance.
Yes, the CS241 has an IP68 rating.