CS241DM

The CS241DM is a surface-mountable, back-of-module temperature sensor with features designed for bifacial photovoltaic (PV) module performance assessment and soiling. The probe head has been redesigned for easier installation. The measurement performance has been improved with a smaller footprint that is 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. To meet the requirements of performance validation, every CS241DM is supplied with a NIST-traceable, serialized calibration certificate. 

This best-in-class smart sensor is a digital Modbus version of the CS241 Pt-1000 Class A, Back-of-Module Temperature Sensor.

The CS241DM 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 CS241DM 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 two percent 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 disk adhesive 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 CS241DM cable has been upgraded to a thin polytetrafluoroethylene (PTFE) Teflon-jacketed cable. This has two distinct advantages:

1. The thin diameter is small enough to fit between the cells of a bifacial module, eliminating any module shading due to cabling.
2. The Teflon jacket allows for a higher maximum temperature rating of 150°C. The cable includes a quick sensor head connection that is 0.91 m (3 ft) from the sensor head to allow for easier installation and sensor head replacement.

Combining the highest-quality components and thoughtful, coherent CS241DM sensor design results in the highest back-of-module temperature-sensor performance. The CS241DM 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 CS241DM includes a NIST-traceable, serialized calibration; alcohol swab; and zip ties that clip to the edge of a module frame.