The CS220 is a 24-AWG, type E thermocouple, typically used for temperature measurements on the back of a solar panel. For temperatures up to 260°C, this fast-response thermocouple adheres to the panel. For temperatures up to 315°C, the CS220 can be cemented to the panel using epoxy.  The thermocouple's tolerance (reference junction at 0°C) is 1.0°C or 0.4 percent (0° to 900°C).