When buying a CO₂ fractional laser machine, the specification sheet may show impressive numbers:
30W or 40W power, RF CO₂ laser source, 200 μs pulse width, 0.2 mm spot size, 10 m/s scanner speed…
But good specifications on paper do not automatically guarantee good real-world output.
For clinic owners, aesthetic professionals, distributors, and equipment buyers, the more practical questions are:
Are the laser spots clean and consistent? Is the full scan area uniform? Does the machine remain stable during repeated firing? Do the advertised scan modes actually work?
If you are still comparing the basic hardware and specifications, start with our How to Evaluate a CO₂ Fractional Laser Machine: 4 Key Things to Check guide, which explains the laser source, pulse width, spot size, and galvanometer scanner.
If specifications such as 200 μs, 20 mJ, and 0.2 mm spot size are still confusing, read CO₂ レーザーのパルス幅 & Spot Size Explained first.
The good news is that you do not need to be a laser engineer to perform a basic pre-purchase inspection.
Even without a professional laser power meter or energy meter, these five practical tests can help you evaluate spot quality, scan consistency, operating modes, and output repeatability before buying a CO₂ fractional laser machine.
Test 1: Single Spot Test — Check Spot Quality and Repeatability
Start with the simplest test.
Instead of immediately testing a large fractional pattern, ask the supplier to fire individual laser spots onto a suitable test material.
Keep the settings and working distance unchanged, and fire several spots:
● ● ● ● ●
Then compare them.
What Should You Look For?
First, check whether the spots are approximately the same size.
If the first spot looks like:
●
the second like:
◉
and the third like:
•
despite using exactly the same settings, the difference deserves further investigation.
Next, examine the spot shape. Look for obvious irregularities such as elongated spots, tails, highly uneven edges, or substantial differences from one pulse to another.
Finally, repeat the test several times.
A machine producing one clean spot is not enough. What matters is whether it can produce similar spots repeatedly under the same conditions.
What Does the Single Spot Test Tell You?
This is primarily a basic:
Spot Quality + Output Repeatability Check
It can help you visually compare spot formation and shot-to-shot consistency.
However, it does ない prove that a machine displaying 20 mJ is actually delivering exactly 20 mJ.
Absolute pulse-energy verification requires appropriate calibrated measurement equipment.
If you want to understand why the same mJ value cannot be evaluated independently of pulse duration and spot diameter, see CO₂ レーザーのパルス幅 & Spot Size Explained。
Test 2: Full-Area Scan Test — Check the Center, Edges and Corners
After checking individual spots, move to a larger:
Square Fractional Pattern
例えば：
● ● ● ● ● ●
● ● ● ● ● ●
● ● ● ● ● ●
● ● ● ● ● ●
● ● ● ● ● ●This test is particularly important because a fractional CO₂ laser does not simply fire one stationary beam.
の galvanometer scanner rapidly positions the laser beam across the treatment field to create the fractional pattern.
Therefore, you need to evaluate more than the center of the scan.
比較する：
Center → Top → Bottom → Left → Right → Four Corners
1. Do the Corner Spots Look Different?
The center may look like:
● ● ●
while a corner may look like:
◉ ◍ ◉
Significant differences across the field deserve further investigation.
2. Do Round Spots Become Elongated?
Pay particular attention to the edges and corners.
If spots are reasonably regular in the center but become obviously stretched near the edge, the scanner, optics, alignment, calibration, or test setup may need to be checked.
3. Is There Visible Tailing?
A spot may sometimes appear to have a small “tail.”
At high scanning speeds, scanner positioning, laser triggering, timing, optics, and system control can all influence the final pattern.
4. Are Any Spots Missing?
例えば：
● ● ● ● ●
● ● ● ●
● ● ● ● ●If missing spots repeatedly appear under the same conditions, further investigation is warranted.
5. Is a Square Still a Square?
If you select a square scan pattern but the actual result appears obviously trapezoidal, skewed, or distorted, the scan system and optical calibration should be examined more carefully.
Don’t Evaluate a Scanner Only by “10 m/s”
Many CO₂ laser machines advertise specifications such as:
Scanner Speed: 10 m/s
That number may be useful, but:
Scanner speed alone does not determine scanner quality.
Other relevant factors include positioning accuracy, repeatability, trigger timing, acceleration and settling behavior, optical alignment, and spot consistency across the scan field.
For a non-engineer, there is a much easier practical test:
Ask the supplier to produce a large fractional pattern and compare the center, edges, and four corners.
If you want to explore this component in more detail, link this section to your upcoming CO₂ Laser Galvanometer Scanner Explained guide:
/blog/co2-laser-galvanometer-scanner/
Do not activate this link until that article is published.
Test 3: Multi-Layer Paper Test — Look Beyond “How Many Sheets?”
の paper burn test is one of the easiest CO₂ laser demonstrations to understand visually.
Several identical sheets of paper can be stacked together and tested using controlled settings.
Keep the following conditions as consistent as possible:
エネルギー
パルス幅
スポットサイズ
Focus Distance
Scan Pattern
Number of Passes
But there is one important mistake to avoid.
Don’t only ask:
“How many sheets can the laser penetrate?”
Instead, separate the sheets after the test and examine them layer by layer。
What Should You Check?
Look at the fractional pattern on each layer.
Compare whether:
The pattern remains complete
Some areas disappear earlier than others
The center behaves differently from the corners
Spot diameter changes significantly
Missing spots appear
There is unusual charring or pattern distortion
This gives you much more information than simply counting the number of sheets penetrated.
Does Penetrating More Paper Mean a Better CO₂ Laser?
必ずしもそうとは限りません。
Paper-test results can be influenced by many variables:
Paper thickness, composition, color, moisture, focus position, pulse width, spot size, energy, number of passes, and contact between layers.
Therefore:
A paper test is more useful as a controlled qualitative comparison than as an absolute energy measurement.
For example, you can use:
the same machine,
the same paper,
the same settings,
and the same test procedure,
then repeat the test three times.
If the three results are reasonably similar, that tells you more about repeatability than a simple claim such as:
“Our laser can penetrate five sheets.”
When comparing different mJ, pulse-width, and spot-size settings, avoid judging the machine solely by the number of paper layers penetrated. See CO₂ レーザーのパルス幅 & Spot Size Explained for a clearer explanation of how these parameters interact.
Paper Layers Do Not Equal Skin Depth
This distinction is important.
You should not convert:
1 sheet of paper
into:
X mm of skin depth
or claim that:
5 sheets = a specific clinical treatment depth.
Paper and human tissue have very different water content, optical absorption, thermal properties, structures, and responses to laser energy.
Therefore:
A paper test can help you visually evaluate output consistency, but it cannot directly predict clinical treatment depth.
Test 4: Random Scan Test — Verify That the Scan Mode Actually Works
If the machine advertises:
Random Scan / Random Mode
ask the supplier to demonstrate it.
In a conventional sequential pattern, spots may be delivered in an ordered sequence such as:
1 → 2 → 3 → 4 → 5
6 → 7 → 8 → 9 → 10A random or distributed scanning strategy changes the sequence so that consecutive laser spots can be spatially separated.
A simplified example might look like:
1 4
7
2
5 8
3
6The actual algorithm varies by machine.
How Can a Buyer Check Random Scan?
One simple method is to record the treatment area using a smartphone in slow-motion video。
If possible, use a slower scanning setting or larger spot spacing so that the firing sequence is easier to observe.
The objective is straightforward:
Verify that switching to Random Scan actually changes the scanning sequence.
A “Random” button on the interface is less meaningful if the advertised operating mode cannot be demonstrated.
Is Random Scan Always Better Than Sequential Scan?
必ずしもそうとは限りません。
Different scanning strategies can serve different operating purposes.
One advantage of a distributed scanning sequence is that consecutive treatment points can be separated spatially rather than always being delivered immediately next to one another.
However, this does not mean:
Sequential scanning automatically causes burns or scarring.
Actual tissue response depends on multiple factors, including energy, pulse width, density, spacing, number of passes, technique, and other treatment conditions.
For equipment inspection, the main purpose of this test is simpler:
Does the machine’s advertised Random Scan function actually operate as intended?
Test 5: Repeated Output Test — Check Stability Over Multiple Shots
After the first four tests, perform one final test:
Repeated Output Testing
This is one of the most useful tests to request before purchasing a CO₂ fractional laser machine.
Why?
Because some machines may produce an excellent-looking pattern once.
The more useful question is:
Can the machine produce a similar result repeatedly?
How to Perform the Test
Keep all relevant settings unchanged:
Energy — Same
Pulse Width — Same
Spot Size — Same
Density — Same
Scan Area — Same
Pattern — Same
Focus Distance — As consistent as possible
Then compare:
Shot 1
Shot 5
Shot 10
Shot 20
Place the results next to one another.
What Should You Look For?
Check whether the apparent spot size changes significantly.
Compare whether the scan pattern begins to distort.
Look for missing spots during later tests.
Check whether the visible burn pattern becomes progressively stronger or weaker under otherwise unchanged test conditions.
Also watch for machine warnings such as:
Laser Error
Scanner Error
Overheating
or other abnormal system alerts.
Why Is Repeatability So Important?
A professional laser system should not be evaluated only by asking:
“What is the maximum energy?”
Another important question is:
“Can the machine reproduce similar output under the same settings?”
Suppose the interface displays:
20 mJ
The important visual check for a normal buyer is not simply whether the screen can display “20 mJ.”
It is whether repeated operation under the same conditions produces reasonably consistent results.
To determine whether the actual pulse energy is precisely 20 mJ, professional calibrated measurement equipment is required.
But even without such equipment, repeated testing can help a buyer examine:
Output Consistency and Repeatability
Bonus Check: Inspect the Articulated Arm
There is another part of a CO₂ laser machine that buyers often overlook:
The Articulated Arm
A CO₂ laser commonly uses a multi-joint articulated arm to transmit the beam from the laser source to the treatment handpiece.
During an inspection, check whether:
The arm moves smoothly
There is excessive resistance or sticking
The arm pulls back strongly when released
The joints feel unusually loose
The treatment head stays where you position it
Different working angles are comfortable to use
A CO₂ laser is not only a laser source.
The practical user experience also depends on the:
Optical Path + Articulated Arm + Scanner + Handpiece
working together properly.
What Do These 5 CO₂ Laser Tests Actually Check?
| Test | What It Helps You Check | Can a Buyer Do It? |
|---|---|---|
| Single Spot Test | Spot shape, consistency and basic repeatability | はい |
| Full-Area Scan Test | Scanner behavior, field consistency and pattern quality | はい |
| Multi-Layer Paper Test | Qualitative output and pattern consistency | はい |
| Random Scan Test | Whether Random Mode actually changes scanning behavior | はい |
| Repeated Output Test | Output consistency during repeated operation | はい |
| Articulated Arm Check | Mechanical handling and positioning | はい |
The main purpose of these tests is not to turn the buyer into a laser engineer.
It is to move the buying process from:
“Show me the specification sheet.”
to:
“Show me how the actual machine performs.”
What These Tests Cannot Prove
These five tests are useful for basic pre-purchase inspection, but they are not laboratory laser measurements。
They cannot independently prove that:
The actual output is exactly 30 mJ
The pulse width is exactly 200 μs
The beam is TEM₀₀
A certain number of paper layers equals a specific skin depth
A particular setting is appropriate for a particular treatment
A visually good test guarantees clinical safety or efficacy
These questions require different forms of calibrated measurement, technical validation, and—in the case of clinical claims—appropriate supporting evidence.
For example, actual pulse energy may be measured with a suitable:
Laser Energy Meter
Average optical power may be checked with an appropriate:
Laser Power Meter
Pulse duration requires measurement equipment suitable for the pulse characteristics of the laser.
5 Common Mistakes When Comparing CO₂ Fractional Lasers
Buyers often focus too heavily on one impressive specification.
例えば：
“40W must be better than 30W.”
必ずしもそうとは限りません。
“0.1 mm must be better than 0.2 mm.”
必ずしもそうとは限りません。
“A 10 m/s scanner must be a high-end scanner.”
Scanner speed alone cannot establish that.
“More paper penetration means deeper skin penetration.”
That conversion is not valid.
“A shorter pulse width always means a better machine.”
Pulse width should not be judged independently of energy, spot size, output mode, and overall system performance.
A more useful framework is:
Laser Source + Pulse Control + Spot Quality + Scanner Performance + Output Repeatability
For a broader explanation of these factors, see our CO₂ Fractional Laser Machine Evaluation Guide。
How to Ask a Supplier for a Useful CO₂ Laser Test Video
If you are buying internationally and cannot visit the factory in person, ask the supplier to record a complete test video.
Don’t settle for:
Machine powers on → screen lights up → handpiece fires → video ends.
That tells you very little about output quality.
Instead, ask:
Please show me the actual CO₂ laser output test using the same machine. I would like to see the single-spot test, full-area fractional pattern, paper test, random scan mode, and repeated output test using the same settings.
Ideally, the video should show:
The machine
The control interface
The selected parameters
The test material
The laser firing
The final pattern
And whenever possible, ask for:
One continuous, unedited video.
That makes it easier to connect the settings shown on the interface with the actual output you see on the test material.
A Simple 5-Step CO₂ Laser Inspection Checklist
If you don’t want to remember every technical detail in this guide, use this simple sequence:
1. Check the Spot
Single Spot Test
Look for clean, consistent, repeatable spots.
2. Check the Edges
Full-Area Scan Test
Compare the center, edges, and four corners.
3. Check the Pattern
Paper / Pattern Test
Look for missing points, distortion, and obvious inconsistencies.
4. Check the Scan
Random Scan Test
Verify that the advertised scanning modes actually work.
5. Check Stability
Repeated Output Test
Keep the settings unchanged and compare repeated results.
The easiest way to remember it is:
Spot → Edge → Pattern → Scan → Stability
Conclusion: Don’t Just Buy the Specifications—Check the Actual Output
Specifications are important when buying a CO₂ fractional laser machine。
You should understand the:
Laser Source, Power, Pulse Width, Pulse Energy, Spot Size, Scanner, Scan Area, and Density.
But specifications are only the first step.
Before purchasing, ask the supplier to:
Show the spot.
Show the full scan area.
Show the scan modes.
Repeat the test.
A good CO₂ fractional laser machine is not simply one with impressive numbers on a specification sheet.
What matters is whether the system can produce output that is clean, consistent, uniform, and repeatable under controlled test conditions。
You do not need to become a laser engineer to perform a basic machine comparison.
Just remember:
Check the Spot → Check the Edges → Check the Pattern → Check the Scan → Check the Stability
If you have finished the technical evaluation and are ready to compare different machine configurations and features, continue to the CO₂ Fractional Laser Machines category page to compare available systems.
Related CO₂ Laser Guides
How to Evaluate a CO₂ Fractional Laser Machine: 4 Key Things to Check
Learn how to evaluate the laser source, pulse width, spot size, and scanner before comparing machines.
CO₂ レーザーのパルス幅 & Spot Size Explained
Understand what μs, mJ, 0.2 mm spot size, and energy density actually mean.
CO₂ Laser Galvanometer Scanner Explained
Learn why scanner speed alone cannot determine scanner quality and what buyers should check instead.
CO₂ Fractional Laser Machines
Compare different CO₂ laser configurations, specifications, and machine options.
