UNI-T UT381PV vs UT673PV Solar Tester Comparison Malaysia
UNI-T UT381PV vs UT673PV Solar Tester Comparison Malaysia
Content
The UNI-T UT381PV and UNI-T UT673PV are both designed for photovoltaic applications, but they measure different parts of a solar panel system.
The UT381PV measures the environmental and installation conditions affecting solar performance. The UT673PV measures the electrical output of an individual solar panel.
For complete solar panel assessment, the two instruments can be used together.
Main Difference
The easiest way to understand the difference is:
- UT381PV: Measures sunlight, temperature, tilt angle and direction
- UT673PV: Measures solar panel power, voltage and current
The UT381PV helps determine the conditions available for solar generation. The UT673PV checks how the panel performs under those conditions.
UNI-T UT381PV Measurement Functions
The UT381PV Solar Irradiance Meter measures:
- Solar irradiance from 0 to 1400 W/m²
- Temperature from −40°C to 120°C
- Panel inclination from −90° to +90°
- Azimuth direction from 0° to 360°
- Ambient and solar panel temperatures
- Installation angle and orientation
It also provides:
- Storage for 12,800 data sets
- Adjustable logging interval
- Bluetooth connection to the iENV App
- IP65 protection
- Two-metre drop resistance
- Quick-release mounting bracket
The UT381PV is suitable for evaluating whether sunlight, panel temperature or installation position may be affecting the system output.
UNI-T UT673PV Measurement Functions
The UT673PV Solar MPPT Meter measures:
- Maximum power up to 800 W
- Peak power voltage from 12 to 60 V
- Peak power current up to 35 A
- Open-circuit voltage
- Short-circuit current
- Manual and automatic MPPT testing
The instrument connects directly to a compatible solar panel using its supplied MC4 test leads.
It is mainly used to check the electrical performance of an individual PV module rather than the environmental conditions surrounding the panel.
Function Comparison
| Test Requirement | UNI-T UT381PV | UNI-T UT673PV |
|---|---|---|
| Solar irradiance | Yes | No |
| Panel temperature | Yes | No |
| Ambient temperature | Yes | No |
| Inclination angle | Yes | No |
| Azimuth direction | Yes | No |
| Maximum panel power | No | Yes |
| Peak power voltage | No | Yes |
| Peak power current | No | Yes |
| Open-circuit voltage | No | Yes |
| Short-circuit current | No | Yes |
| Data storage | 12,800 sets | Not the main function |
| Mobile App connection | iENV | No |
| Direct MC4 connection | No | Yes |
| Outdoor protection | IP65 | Refer to product configuration |
Neither instrument replaces every electrical safety test required for a complete photovoltaic installation.
When to Choose the UT381PV
Choose the UT381PV when the main requirement is to:
- Measure available sunlight
- Check panel surface temperature
- Compare ambient and panel temperatures
- Verify panel tilt angle
- Check panel orientation
- Record environmental data
- Investigate shading or installation issues
- Support solar site inspection reports
It is particularly useful for installers, maintenance technicians, consultants and PV testing teams.
When to Choose the UT673PV
Choose the UT673PV when the main requirement is to:
- Test individual solar panels
- Measure maximum panel power
- Check peak power voltage and current
- Measure open-circuit voltage
- Measure short-circuit current
- Compare panel performance
- Check a panel before installation
- Investigate a suspected weak module
The UT673PV is intended for compatible panels within its specified voltage, current and power limits.
Why Use Both Instruments?
Suppose a solar panel produces less power than expected.
The UT673PV may confirm that its measured maximum power is low. However, this result alone does not explain whether the cause is:
- Weak sunlight
- High panel temperature
- Incorrect panel angle
- Wrong orientation
- Partial shading
- Dirt on the panel
- An actual module problem
The UT381PV provides the environmental information needed to interpret the electrical result.
A practical combined test is:
- Measure solar irradiance with the UT381PV.
- Record the ambient and panel temperatures.
- Check the panel inclination.
- Verify the azimuth direction.
- Connect the UT673PV to the compatible panel.
- Measure maximum power, voltage and current.
- Compare the environmental conditions with the electrical result.
- Repeat the test on another panel when required.
This approach provides a clearer assessment than using either instrument alone.
Important Safety Considerations
Before connecting a tester to a solar panel:
- Confirm the panel voltage, current and power ratings
- Check that they are within the instrument’s limits
- Inspect the MC4 leads and connectors
- Follow the correct connection procedure
- Avoid disconnecting live connectors improperly
- Use appropriate personal protective equipment
- Follow the site’s electrical safety procedures
The UT381PV does not make electrical contact with the solar circuit, while the UT673PV connects directly to the panel for electrical testing.
Which Model Is Better?
Neither model is a direct replacement for the other.
Choose UT381PV for environmental and installation measurements. Choose UT673PV for portable electrical performance testing of compatible individual solar panels.
For solar contractors who regularly perform installation, commissioning and troubleshooting, keeping both instruments provides a more complete testing solution.
For assistance choosing between the UNI-T UT381PV and UT673PV for solar panel testing in Malaysia, contact MTM Precision.
MTM Precision Sdn Bhd
Showroom & Service Centre: No. 29-1 & 29-2, Jalan Bandar 18, Pusat Bandar Puchong, 47160 Puchong, Selangor, Malaysia
Tel: 03-8080 7172
WhatsApp: +6016-660 7346
Email: mtmpre@yahoo.com
Website: www.mtmpre.com.my
30 Sep 2026
