Metrel A1427 is an irradiance sensor for PV measurements. The reference cell is also used for measuring the irradiance. The reference cell is created similar to the Photovoltaic system. A reference cell is made up of PV cells, encapsulant, back sheet and glass. If the reference cell is tested, then the reference cell's spectral and angular response closely matches the PV system of similar specifications. It is a must-have accessory for Photovoltaic Tester. The reference cell is used to determine the value of the electricity that a PV system would generate. Metrel has a history of producing precise and quality instruments throughout its operating lifespan. Product Features: Brand: Metrel Model: A1427 Product: Optional Accessories for Photovoltaic Tester Type: PV Reference Cell