Solar Irradiance Meter Malaysia How to Measure Solar Radiation in W/m
Solar Irradiance Meter Malaysia – How to Measure Solar Radiation in W/m²
A solar irradiance meter is used to measure the amount of solar power reaching a surface, normally expressed in watts per square metre (W/m²).
For solar PV installers, electrical contractors and maintenance technicians in Malaysia, this measurement can provide important information when assessing sunlight conditions, comparing different locations or investigating photovoltaic system performance.
The VICI LX-107 Solar Power Meter is a portable instrument designed for solar radiation measurement and is suitable for field, research and industrial applications.
What Is Solar Irradiance?
Solar irradiance describes the solar power received over a given area.
It is commonly expressed as:
W/m² – watts per square metre
A higher W/m² reading generally indicates stronger solar radiation reaching the measurement surface at that moment.
Solar irradiance should not be confused with electrical output from a solar panel.
Solar irradiance measures the incoming solar energy.
PV electrical instruments measure the electrical performance produced by the solar system.
Using both types of information can provide a better understanding of PV system conditions.
Why Measure Solar Irradiance During PV Testing?
Imagine that a technician measures a solar panel or PV string and finds that the electrical output is lower than expected.
There are at least two very different possibilities:
1. Solar radiation is low
Cloud cover, time of day, panel orientation or temporary shading may reduce the available sunlight.
2. Solar radiation is strong, but PV output remains abnormal
The technician may then need to investigate other factors such as contamination, shading, wiring, module condition, connections or other system issues.
This is why recording solar irradiance in W/m² at the time of testing can provide useful context for PV inspection and troubleshooting.
How to Measure Solar Irradiance in W/m²
The basic measurement process is straightforward.
Step 1 – Select W/m²
Set the solar power meter to the required measurement unit.
For most solar PV applications, W/m² is the most useful unit.
Step 2 – Position the Sensor
Position the sensor at the location and orientation relevant to the measurement.
When comparing conditions with a solar module, sensor orientation is important. A sensor pointed in a different direction from the PV module may receive different solar radiation.
Step 3 – Avoid Accidental Shading
Do not stand where your body, equipment or nearby objects shade the sensor.
Even temporary shading can significantly change the reading.
Step 4 – Allow the Reading to Stabilise
Observe the displayed value.
Outdoor solar radiation can change quickly, especially when clouds are moving across the sun.
Step 5 – Record the Irradiance
Record the W/m² reading together with the time and test location.
For more useful PV troubleshooting records, technicians can also note weather conditions and the corresponding electrical measurements.
Example of a Solar Irradiance Reading
Suppose a technician is inspecting a rooftop solar system.
The solar power meter shows:
Solar irradiance: 950 W/m²
The technician can record this reading together with the PV electrical measurements taken at approximately the same time.
If another test is performed later when the irradiance is only 450 W/m², directly comparing the two electrical outputs without considering the different sunlight conditions could be misleading.
This is one reason solar irradiance measurement is useful during PV inspection.
Solar Irradiance Can Change Quickly
Malaysia's weather can produce rapidly changing outdoor measurement conditions.
A clear sky can become cloudy within minutes, while passing clouds can cause noticeable changes in solar radiation.
Therefore, for field troubleshooting, it is useful to take the irradiance measurement close to the time of the corresponding PV measurement.
Do not assume that a reading taken much earlier represents the same conditions.
VICI LX-107 for Solar Radiation Measurement
The VICI LX-107 Solar Power Meter provides portable solar radiation measurement for field and technical applications.
The instrument supports:
W/m² display
Useful for solar irradiance measurement and PV-related applications.
BTU display
Provides an alternative unit for applications requiring BTU-based measurement.
MAX / MIN
Useful for observing variations during a measurement period.
Data Hold
Allows a displayed value to be held for convenient reading or recording.
Its portable format makes it suitable for technicians who need to move between different measurement points.
Where Can a Solar Irradiance Meter Be Used?
A handheld solar power meter can be useful for many applications in Malaysia.
Rooftop Solar PV
Measure solar radiation during installation, inspection or troubleshooting.
Commercial and Industrial Solar
Support measurements on factory, warehouse and commercial rooftop PV projects.
Solar Site Comparison
Compare solar radiation at different locations or orientations.
Solar Research
Useful for educational institutions, laboratories and solar-related experiments.
Agriculture
Solar radiation measurements can support agricultural and environmental studies.
Window and Glass Evaluation
Solar power measurement can also be used when comparing solar radiation through different windows or glazing materials.
Meteorological Applications
Solar radiation is an important environmental measurement for certain weather and research activities.
Solar Irradiance Meter vs Lux Meter
These instruments should not automatically be treated as interchangeable.
A lux meter measures illuminance as perceived according to the response of the human eye and reports the result in lux.
A solar power or irradiance meter measures solar power per unit area and reports values such as W/m².
For solar PV work where the objective is to understand incident solar power, a solar irradiance measurement is generally more relevant than a normal lux reading.
Solar Irradiance Meter for Solar Installers
For a solar installer, the irradiance meter can become a useful companion instrument alongside other PV and electrical testing equipment.
A practical field kit may include instruments for:
Solar irradiance
DC voltage
DC current
Electrical safety testing
Temperature
Thermal inspection
Insulation testing
PV-specific electrical measurements
The exact equipment required depends on the type of solar installation and testing procedure being performed.
Choosing a Solar Irradiance Meter in Malaysia
Before purchasing, consider:
Measurement unit – Is W/m² supported?
Measurement range – Is it suitable for outdoor solar radiation?
Portability – Will technicians regularly use it on rooftops or field sites?
Hold function – Can readings be conveniently recorded?
MAX/MIN function – Is variation monitoring useful for the application?
Application – Is the instrument intended for PV, research, agriculture, meteorology or another purpose?
The lowest-priced meter is not automatically the best choice. The instrument should match the actual measurement requirement.
Solar Irradiance Meter Supplier Malaysia
MTM Precision supplies testing and measurement instruments for solar installers, electrical contractors, engineers, factories, facility teams and industrial users in Malaysia.
For users looking for a portable solar radiation instrument, the VICI LX-107 Solar Power Meter is one option for measuring solar power in W/m².
Contact MTM Precision
MTM Precision Sdn Bhd
Website: www.mtmpre.com.my
Email: mtmpre@yahoo.com
WhatsApp: 016-660 7346
Showroom & Service Centre
No. 29-1 & 29-2, Jalan Bandar 18,
Pusat Bandar Puchong,
47160 Puchong, Selangor, Malaysia.
Serving customers throughout Selangor, Kuala Lumpur, Johor, Penang, Perak, Negeri Sembilan, Melaka, Pahang, Kedah, Perlis, Terengganu, Kelantan, Sabah and Sarawak.
Need a solar irradiance meter for PV testing in Malaysia? Contact MTM Precision for VICI LX-107 product information, availability and suitable solar testing instrument recommendations.
08 Sep 2026
