PV Reference Cell / Solar Irradiance Sensor PV Monitoring

Photovoltaic Reference Cells for PV Monitoring

Our photovoltaic reference cells offer an economical but robust and reliable solution for measuring solar irradiance levels, particularly for monitoring photovoltaic systems. The design of these silicon solar irradiation sensors (Si sensors), which corresponds to that of a photovoltaic module, make these sensors ideally suited as a reference for monitoring photovoltaic systems. The spectral sensitivity, which corresponds to that of photovoltaic modules, and the very similar incident angle modifier, enable a precise analysis of photovoltaic yields using measured values from the sensor.

We have been manufacturing various types of Si sensors since 1994. So far, we have sold several 10,000 pv reference cells worldwide.

The Measurement Uncertainty of all Si sensors is class A as per IEC 61724-1. The Measurement Uncertainty of our pv reference cells with temperature compensation depends on the sensor type. The digital Si sensor have in the range of 0 to 1500 W/sqm a uncertainty of ±0.4 W/qm ± 1.6% of reading.

All our pv reference cells have consistent measuring ranges of the solar irradiance (0 to 1500 W/sqm) and the internal temperature of the sensor cell (-40 to +90°C).

Current Data



Irradiance Signal 
0…1500 W/sqm
Cell Temperature Signal
Si-V-1.5TC-batt-D / -E1Class Abatteryyes0...1.5 V---
Si-V-1.5TCClass A4...28 Vdcyes0...1.5 V---
Si-V-1.5TC-TClass A5.5...28 Vdcyes0...1.5 V0...2 V
Si-mV-85Class Anoneno0...approx. 85 mV---
Si-mV-85-Pt100 / -4L2Class Anoneno0...approx. 85 mVPt100
Si-mV-85-Pt1000 / -4L2Class Anoneno0...approx. 85 mVPt1000
Si-I-420TCClass A12...28 Vdcyes4...20 mA---
Si-I-420TC-TClass A12...28 Vdcyes4...20 mA4...20 mA
Si-V-10TCClass A12...28 Vdcyes0...10 V---
Si-V-10TC-TClass A12...28 Vdcyes0...10 V0...10 V
Si-RS485TC-TClass A10...28 VdcyesRS485RS485
Si-RS485TC-2T 3Class A10...28 VdcyesRS485RS485
Si-RS485TC-3T 4Class A10...28 VdcyesRS485RS485
Si-RS485TC-T-Tm 5Class A10...28 VdcyesRS485RS485
Si-RS485TC-2T-v 6Class A10...28 VdcyesRS485RS485

1 "-batt": Version not usuable for outdoor installation. Only for laboratory and toolbox.
2 "-4L": Version with four wire connection of Pt100 / Pt1000

Notes about Digital Sensor:
3 for Si-RS485TC-2T: Fixed connected ambient temperature sensor  Pt1000 with 3 m cable 
4 for Si-RS485TC-3T: Two connector for two temperature sensor (Tamb-Si or Tmodul-Si)

5 for Si-RS485TC-T-Tm: Fixed connected module temperature sensor Pt1000 with 3 m cable 
6 for Si-RS485TC-2T-v: Connector for one temperature sensor (Tamb-Si or Tmodul-Si) and one wind speed sensor (Vwind-Si)

Addendum -MB in type designation: Modbus protocol
Addendum -MT in type designation: M&T protocol

A selection table with notes with the correct digital Si sensor and optional external sensor you can find here.

Optional Sensor for Connection with Si-RS485TC-2T-v:
Module Temperature Sensor: Tmodul-Si (Pt1000)
Ambient Temperature Sensor: Tamb-Si (Pt1000)
Weather Protection for Ambient Temperature Sensor: Shield Tamb-Si
Windspeed Sensor: Vwind-Si



Add-ons Si-Series

Modbus Instructions