Measurement system for I-V curve of PV modules or strings



Photozig is a portable test system designed to measure the current-voltage (I-V) curves of PV modules and strings . The measured curve is automatically normalized to standard reference conditions and compared to nominal data supplied by the module manufacturer, with an immediate response of the test.

Measurement results can be easily saved and compared over time to evaluate the performance of modules and facilitate maintenance of the photovoltaic generator.

The use of newer technologies (wireless connections, high-speed converters, variable capacitive load) make Photozig an easy to use tool for high performance measurements. Finally, just add to Photozig the optional volt-amperometric clamps and it also becomes capable of testing the entire PV system, inverters included (Solarzig system).




Key features


- Visualization of the I-V and P-V curves of the PV module or string with immediate indication of the outcome of the test. Automatic calculation of: Voc, Isc, Vmpp, Impp, Pmax, FF, Rs, Rsh

- Full-wireless connection (irradiance sensor, temperatures and electrical signals) for maximum safety and ease of installation

- Internal database with over 3000 commercial PV modules

- Full integration with the Solarzig system for the verification of performance of the entire PV plant

- Automatic generation of the test report (pdf format) with numerical and graphical data


- The I-V curve of the PV generator is captured by the IV01 tracer; a wireless device designed for maximum ease of installation and operator safety

The number of points of the characteristic curve can be set in a range between 128 (low resolution) and 1024 points (high resolution). The range of current and voltage signals and the internal load capacitance value is selected automatically by the instrument; all that is required to perform a complete measurement is just sending the appropriate command from the PC program.


Advantages of a PC-based instrument

- Graphics and processing capabilities far superior to a stand-alone tool

- Simplification of the measure; all data during the test are replicated in the memory of your PC, you do not require any additional procedure of downloading

- Extreme versatility; it is sufficient to change the type of sensors and use the appropriate software to obtain a new complete measuring system suitable for a different application (for example Solarzig system or Thermozig system)

- Instrument always up to date. Since the calculations are performed by software in PC, in case of any developments concerning new regulations or new instrument features options you just load the latest version of the program, provided free of charge to Optivelox's customers


  Field tests

PHOTON Laboratory GmbH has made a comparative test between the main instruments for the measurement of the I-V characteristics. During the months of July and August 2012 Photon has published the results of tests on their magazines.

The following table summarizes the assessment for each instrument:


WS: instrument with wireless solarimeter
WT: instrument with wireless I-V tracer


  Standard configurations



The Photozig system includes software and all accessories necessary for verification of the performance of a photovoltaic generator. The PC is not included in the supply, may be ordered as option.

To transform the system Photozig in Solarzig is sufficient to add a pair of volt-amperometric clamps FE03/FE04 (or FE03H/FE04H for high power plants).


Photozig includes:

- 1x Datalogger DL02 (complete with manual, software and PC interface cable)
- 1x Meteo Station SM01-P (with a radio modem RM01-P included)
- 2x Radio Modem RM01-P (with internal rechargeable battery)
- 1x IV01 (I-V curve tracer)
- 1x Test clip adapter cable set
- 1x MC4 adapter cable set
- 1x AC power supply
- 1x Photozig Reference Guide
- 1x Software suite PVtest + PVreport
- 1x Carrying case


Download Photozig Overview
Download IV01 Data Sheet