In today’s increasingly DIY-focused world, having reliable testing equipment is essential for both amateur enthusiasts and professionals alike. The INNOVA 3320 Auto-Ranging Digital Multimeter has established itself as one of the most popular budget multimeters on the market, with thousands of users relying on it for various electrical testing needs. As someone who has extensively worked with electrical testing equipment over the years, I was eager to evaluate this widely-used multimeter to determine if its popularity is justified by its performance.
The INNOVA 3320 occupies an interesting position in the market – it’s significantly more affordable than professional-grade equipment like Fluke meters, yet offers features beyond basic entry-level testers. This review aims to provide a thorough examination of the INNOVA 3320’s capabilities, build quality, reliability, and overall value proposition for different user categories.
Design and Build Quality
Physical Characteristics
The INNOVA 3320 features a compact design that’s smaller than it might appear in product photos. Measuring approximately 1½” x 5¼” x 3″, it’s considerably more portable than many other multimeters, making it convenient to carry in a toolbox or a utility drawer. The unit weighs approximately 180g (6.3oz) with the included AA batteries installed, striking a good balance between sturdiness and portability.
The device features a black casing with distinctive red rubber corner protectors that serve as both aesthetic elements and impact absorption. These protective corners give the meter a rugged appearance and provide some drop protection, though not to the same degree as higher-end professional units.
Display
One of the standout features of the 3320 is its large, easy-to-read LCD display with 1½” numerals that are clearly visible even from a distance. This is particularly beneficial for those with vision limitations or when working in awkward positions where viewing the meter might be challenging. However, it’s worth noting that the display lacks backlighting, which can be problematic when working in dimly lit environments.
Controls and Ergonomics
The multimeter features a central rotary dial that allows users to select between different measurement functions. The dial feels adequate, though not as precise or substantial as those found on more expensive models. The function indicators on the dial face are clear and well-labeled, with helpful color-coding that makes selecting the right function relatively intuitive.
On the back of the unit, you’ll find both a fold-out stand and an elastic wrist strap. The stand allows the meter to be propped up at a 45-degree angle for easier viewing when placed on a flat surface. Meanwhile, the elastic strap enables hands-free operation by securing the meter to your wrist or forearm, freeing up both hands for probe placement. While innovative, some users report that the elastic band is of lower quality and may stretch out over time.
A minor but consistently mentioned issue involves the rubber probe holders on the sides of the unit. These holders are intended to secure the test leads when not in use, but they’re often too soft and flexible to maintain a firm grip on the probes, causing them to fall out with minimal movement or when placed in a toolbox.
Features and Functionality
Measurement Capabilities
The INNOVA 3320 offers a comprehensive set of measurement capabilities for a meter in its price range:
- AC & DC voltage measurements up to 600V max, with auto-ranging across multiple scales (200mV, 2V, 20V, 200V, 600V)
- AC & DC current measurements with fused protection for lower ranges (20mA, 200mA) and unfused higher DC current measurements (2A, 10A)
- Resistance measurements across multiple ranges (200Ω, 2kΩ, 20kΩ, 200kΩ, 2MΩ, 20MΩ)
- Diode testing with approximately 1mA test current at 1.5VDC
- Continuity testing with audible indication at 120Ω or less
- Battery testing with load for 1.5V, 6V, 9V, and 12V batteries
The auto-ranging functionality is particularly noteworthy as it automatically selects the appropriate measurement range, eliminating the need to manually set ranges as with more basic multimeters. This makes the device significantly more user-friendly, especially for those who are less experienced with electrical testing.
Battery Testing Function
A distinctive feature of the INNOVA 3320 is its battery testing capability with integrated load testing. Unlike basic voltage measurement, this function applies a small load to the battery being tested (10mA for 1.5V and 9V batteries, 100mA for 6V batteries, and 200mA for 12V batteries) and provides a three-LED indicator system (green/yellow/red) to quickly assess battery condition.
This feature is particularly useful for household battery management, allowing users to quickly sort through batteries to determine which are still usable. However, it’s important to note that several users report this function failing over time, with the LED indicators ceasing to work after months or years of use. Additionally, this function isn’t suitable for testing car batteries under cranking load – it’s primarily designed for household battery evaluation.
Auto-Off Function
The 3320 includes an auto power-off feature that turns the meter off after approximately 15 minutes of inactivity. This helps preserve battery life when the unit is accidentally left on, a common occurrence with test equipment. Before shutting down, the meter emits warning beeps to alert the user.
Performance and Accuracy
Measurement Accuracy
For a budget-friendly multimeter, the INNOVA 3320 delivers surprisingly accurate readings across most of its measurement ranges. When compared against higher-end calibrated equipment like Fluke meters, many users report minimal variance in measurements for standard voltage and resistance readings.
The meter demonstrates excellent performance in typical household and automotive voltage ranges (1.5V to 240V), with readings that are generally within 1-2% of actual values. Resistance measurements are similarly reliable for most common applications, though some users note inconsistencies when measuring very low resistance values (below 1Ω) or extremely high resistance (above 10MΩ).
Current measurements are adequate for basic applications but may be less reliable at the extremes of its range. Additionally, the meter is limited to 200mA for AC current measurements, which may be insufficient for some applications requiring higher current testing.
Response Time and Stability
The auto-ranging function works reasonably quickly, typically settling on the appropriate range within 1-2 seconds. This is notably faster than many other auto-ranging multimeters in the same price bracket, which can take significantly longer to stabilize readings.
One quirk mentioned by some long-term users is that the meter may occasionally develop erratic readings or sluggish auto-ranging performance. Interestingly, many report that rotating the mode selection dial back and forth several times resolves this issue, suggesting it may be related to contact accumulation under the dial.
Continuity Testing
The continuity test function provides an audible beep when a complete circuit is detected, which is invaluable for quickly identifying breaks in wiring or checking fuses. However, unlike professional-grade meters that provide instant feedback, the 3320’s continuity detection has a slight delay of approximately half a second. While this doesn’t affect accuracy, it means that quick probe movements across multiple test points might not register properly.
Reliability and Durability
Long-term Performance
Based on numerous user experiences spanning several years, the INNOVA 3320 generally demonstrates good reliability for its price point. Many users report their units continuing to function accurately after 5+ years of occasional use, making it a reasonable long-term investment for the casual user.
However, the reliability picture isn’t uniformly positive. Some users report failures within the first year, with particular emphasis on the battery test function’s LED indicators failing relatively early. Others mention issues with the internal fuse breaking during shipping or early use, requiring replacement before the meter can function properly in all modes.
Battery Life
The meter operates on two AA batteries, which are typically included with purchase. Battery life is generally excellent, with many users reporting months or even years of intermittent use from a single set of batteries. Some users even report successfully using rechargeable NiMH batteries (which provide 1.2V instead of the standard 1.5V from alkalines) without any performance issues.
The battery compartment requires removing two small Phillips screws to access, which is less convenient than tool-free battery compartments found in some other models. This design has led to some users inadvertently allowing batteries to corrode inside the unit when not checked regularly.
User Experience
Ease of Use
For novice users, the INNOVA 3320 offers a relatively gentle learning curve. The auto-ranging functionality eliminates one of the most common points of confusion for multimeter newcomers, and the clear function markings on the dial face help guide users to the appropriate setting for their needs.
The large display contributes significantly to user-friendliness, as it allows readings to be easily viewed from various angles and distances. The wrist strap feature, while simple, proves surprisingly useful in practical applications where both hands are needed to position probes.
Documentation
A common criticism involves the documentation provided with the meter. Many users report receiving minimal or no printed instructions with recent purchases, with manufacturers instead including a QR code linking to online documentation. Unfortunately, some users report these links being broken or difficult to access.
When available, the manual is described as adequate but basic, with limited troubleshooting information. For users unfamiliar with multimeter operation, supplementary online research or video tutorials may be necessary to fully utilize all functions.
Value Proposition
Price-to-Performance Ratio
With a typical retail price between $18-30 (as of this writing), the INNOVA 3320 offers exceptional value for most casual users. It provides functionality that would have cost significantly more just a decade ago, including auto-ranging, which typically commanded premium prices in the past.
When compared to professional-grade meters like those from Fluke (which often start at $150+), the 3320 certainly lacks advanced features, precision at extremes, and bulletproof reliability. However, for typical home, automotive, and basic electronic applications, the practical difference is minimal for most users.
Target Users
The INNOVA 3320 is best suited for:
- DIY Homeowners: For testing outlets, switches, batteries, and basic household electrical troubleshooting
- Automotive Enthusiasts: For diagnosing 12V electrical systems, testing sensors, and basic automotive electrical work
- Casual Electronics Hobbyists: For basic component testing and low-voltage circuit troubleshooting
- Budget-conscious Professionals: As a secondary or backup meter for non-critical applications
It’s less suitable for:
- Professional Electricians: Who require certified safety ratings and absolute reliability
- Advanced Electronics Work: Where precise measurements of very small values are required
- Industrial Applications: Where harsh environments demand more rugged construction
- High-current AC Testing: Due to its 200mA AC current limitation
Pros and Cons Summary
Pros:
- Excellent price-to-performance ratio
- Auto-ranging functionality eliminates manual range selection
- Large, easy-to-read display
- Battery load testing feature with LED indicators
- Compact size with protective rubber corners
- Useful ergonomic features (stand and wrist strap)
- Good battery life with standard AA batteries
- Accurate for most common household and automotive applications
Cons:
- No display backlighting for low-light conditions
- Battery test function prone to failure over time
- Probe holders on sides offer insufficient grip
- No manual range selection option
- Battery compartment requires screwdriver access
- Limited to 200mA for AC current measurements
- Documentation could be more comprehensive
- Some quality control inconsistencies reported
Conclusion
The INNOVA 3320 Auto-Ranging Digital Multimeter earns its popularity through a well-balanced combination of functionality, ease of use, and affordability. While it doesn’t compete with professional-grade instruments in terms of precision or durability, it delivers surprisingly competent performance for the vast majority of applications most users will encounter.
For homeowners, DIY enthusiasts, and even casual professionals, the 3320 represents an excellent entry point into electrical testing without breaking the bank. Its auto-ranging functionality and intuitive design make it accessible to beginners, while its measurement capabilities are sufficient for most common applications.
The most significant drawbacks – including the lack of backlighting, weak probe holders, and occasional quality control issues – are generally acceptable compromises given the price point. However, users requiring absolute reliability or specialized measurement capabilities would be better served by investing in higher-end equipment.
In essence, the INNOVA 3320 strikes an impressive balance between affordability and functionality, making advanced electrical testing accessible to the average consumer. While not without flaws, it earns a solid recommendation for casual users seeking a versatile, user-friendly multimeter that won’t empty their wallet.
Overall Rating: 4.2/5
For most users seeking an affordable, feature-rich multimeter for occasional use, the INNOVA 3320 represents an excellent value and earns our recommendation as one of the best options in its price category.
Buy on Amazon: Here
