Fluke 59 MAX vs 59 MAX+: What’s the Difference?

The Fluke 59 MAX and Fluke 59 MAX+ look almost identical and share most of their features, but the “+” model has three meaningful upgrades: a higher maximum temperature, better distance-to-spot ratio, and tighter specified accuracy.

The Fluke 59 MAX measures from -30°C to 350°C and uses 8:1 optics. The 59 MAX+ extends the upper limit all the way to 500°C and improves the distance-to-spot ratio to 10:1.

The MAX+ is also rated for ±1.5°C or ±1.5% accuracy at temperatures of 0°C and above, compared with ±2°C or ±2% for the regular MAX.

Otherwise, the two thermometers are remarkably similar. Both have adjustable emissivity, MIN/MAX/AVG/DIF functions, high and low alarms, a single laser, a backlit display, one-AA-battery operation and the same compact housing.

Bottom line: We would choose the Fluke 59 MAX+ if the price difference is modest. The improved optics and accuracy are useful on almost every measurement, while the 500°C range gives you considerably more headroom for automotive and industrial work.

The regular 59 MAX remains a good choice if you mostly measure HVAC equipment, appliances and other surfaces well below 350°C and can buy it substantially cheaper.

Fluke 59 MAX vs 59 MAX+ Quick Comparison

Feature	Fluke 59 MAX	Fluke 59 MAX+
Temperature range	-30°C to 350°C	-30°C to 500°C
Fahrenheit range	-22°F to 662°F	-22°F to 932°F
Distance-to-spot ratio	8:1	10:1
Accuracy at 0°C and above	±2°C or ±2%	±1.5°C or ±1.5%
Repeatability	±1% or ±1°C	±0.8% or ±1°C
Response time	<500 ms	<500 ms
Emissivity	Adjustable 0.10 to 1.00	Adjustable 0.10 to 1.00
Display resolution	0.1°C	0.1°C
Laser	Single	Single
MIN/MAX/AVG/DIF	Yes	Yes
High/low alarms	Yes	Yes
Battery	1 × AA	1 × AA
Rated battery life	12 hours	12 hours
Drop rating	1 meter	1 meter
IP rating	IP40	IP40
Weight	220 g	220 g
Best for	General HVAC and troubleshooting	Higher temperatures and more demanding measurements

The Biggest Difference Is the Temperature Range

The Fluke 59 MAX measures:

-30°C to 350°C (-22°F to 662°F)

The Fluke 59 MAX+ measures:

-30°C to 500°C (-22°F to 932°F)

The low-temperature limit is identical, but the MAX+ adds another 150°C, or 270°F, at the upper end.

For many users, that extra range will never be required.

If you are checking:

• HVAC supply and return vents
• Refrigeration equipment
• Electrical breakers
• Motors
• Pumps
• Household appliances
• Radiators
• Hot-water pipes
• Automotive cooling systems

the 350°C limit of the regular 59 MAX is already more than enough.

The MAX+ becomes more attractive when you start measuring hotter equipment such as:

• Exhaust components
• High-temperature heating elements
• Ovens and furnaces
• Industrial process equipment
• Hot machinery
• Automotive exhaust systems
• High-temperature manufacturing equipment

A 350°C maximum sounds very high until you start working around engines, exhaust systems or industrial heat sources.

Winner: Fluke 59 MAX+

The 59 MAX+ Has Better 10:1 Optics

This may actually be the most useful MAX+ improvement for everyday users.

The Fluke 59 MAX has an 8:1 distance-to-spot ratio.

The Fluke 59 MAX+ improves this to 10:1.

Distance-to-spot ratio tells you approximately how large an area the thermometer measures from a given distance.

With an 8:1 thermometer, standing approximately 8 inches from a target produces a measurement spot approximately 1 inch across.

With a 10:1 thermometer, you can move approximately 10 inches away while measuring roughly the same one-inch spot.

The advantage becomes more noticeable as distance increases.

At 40 inches away:

• 8:1 optics produce roughly a 5-inch measurement spot
• 10:1 optics produce roughly a 4-inch measurement spot

That makes the MAX+ somewhat better at isolating smaller objects from farther away.

This can be useful when checking individual components in an electrical panel, pipes, motor housings or other targets where you do not want the thermometer averaging the temperature of a large surrounding area.

Neither model should be considered a long-distance precision thermometer, however. For that, Fluke models with 12:1, 30:1 or even tighter optics are more appropriate.

The laser also does not indicate the full measurement area. It simply helps you aim at the approximate center of the target.

Winner: Fluke 59 MAX+

The 59 MAX+ Is More Accurate on Paper

There is another significant difference that is easy to overlook.

At temperatures of 0°C and above, Fluke rates the 59 MAX at:

±2.0°C or ±2.0% of the reading, whichever is greater

The 59 MAX+ improves this to:

±1.5°C or ±1.5% of the reading, whichever is greater

That is a real specification improvement.

For example, at a measured temperature of 300°C:

• 59 MAX percentage specification corresponds to ±6°C
• 59 MAX+ percentage specification corresponds to ±4.5°C

That does not mean every MAX+ will always read exactly 1.5°C closer to the true temperature. Infrared measurement accuracy depends heavily on the surface, emissivity, target size, distance and environmental conditions.

But all else being equal, the MAX+ has the tighter factory specification.

Its repeatability specification is also slightly better.

The 59 MAX is rated at ±1.0% of the reading or ±1°C, whichever is greater.

The MAX+ improves the percentage component to ±0.8%, although the ±1°C minimum remains.

Winner: Fluke 59 MAX+

Both Have Adjustable Emissivity

There is no difference here.

Both the Fluke 59 MAX and 59 MAX+ allow emissivity to be adjusted between:

0.10 and 1.00

This is an important feature if you measure different types of materials.

Infrared thermometers determine temperature by measuring infrared energy radiated from a surface. Different materials emit infrared energy differently.

Painted surfaces, rubber, plastics, wood and many non-metallic materials generally have relatively high emissivity.

Bare and polished metals can have much lower emissivity.

If the thermometer’s emissivity setting does not reasonably match the surface, the displayed temperature can be considerably different from the actual temperature.

This is why adjustable emissivity makes both MAX models substantially more versatile than basic infrared thermometers with emissivity permanently fixed at 0.95.

For very shiny metallic surfaces, even adjustable emissivity does not solve every problem. Applying matte electrical tape or another known high-emissivity material to the measurement point can often provide a more reliable reading.

Winner: Tie

Measurement Modes Are the Same

Both thermometers provide:

• MIN
• MAX
• AVG
• DIF
• High-temperature alarm
• Low-temperature alarm

MAX mode can be particularly helpful when scanning several electrical breakers or components and trying to locate the hottest one.

MIN is useful when searching for a cold area.

AVG provides an average reading over the measurement period.

DIF shows the difference between the maximum and minimum temperatures detected.

These functions make both models more useful for troubleshooting than a basic point-and-shoot temperature gun.

There is no advantage to buying the MAX+ specifically for these functions.

Winner: Tie

Both Use a Single Laser

Despite the “+” designation, the 59 MAX+ does not add dual lasers.

Both models use a single aiming laser.

If you specifically want dual-laser targeting, you need to move farther up Fluke’s infrared thermometer range, such as to the 62 MAX+.

The laser should also not be confused with the actual measurement spot.

The infrared sensor measures an area that gets progressively larger as you move away from the object. The laser simply indicates the general center of that area.

This is particularly important with the 59 MAX because of its relatively modest 8:1 optical ratio.

Winner: Tie

Battery Life Is Identical

Both thermometers use a single AA battery.

Fluke rates both models for approximately 12 hours with the laser and backlight operating.

That is a convenient arrangement for a professional tool because AA batteries are inexpensive and readily available.

Both models are considerably easier to keep powered in a service bag than instruments using unusual battery formats.

Winner: Tie

Size and Weight Are Essentially Identical

There is no portability penalty for buying the MAX+.

Fluke specifies both models at approximately:

156 × 80 × 50 mm

and:

220 grams

The housing design is also very similar.

Both fit comfortably into a tool bag and are small enough that there is little reason to choose one over the other based on portability.

Winner: Tie

Durability Is the Same

Both the 59 MAX and MAX+ are specified to survive a one-meter drop.

Both also carry an IP40 rating.

IP40 means the enclosure provides protection against solid objects larger than approximately 1 mm but does not carry a water-ingress protection rating.

In practical terms, these are service and workshop instruments rather than waterproof outdoor thermometers.

They should handle normal toolbox use, but neither is intended to be submerged or routinely exposed to rain.

Winner: Tie

What Customers Say About the Fluke 59 MAX and 59 MAX+

Customer feedback on these thermometers is somewhat more complicated than the specifications suggest.

There are plenty of satisfied owners, but there are also several surprisingly negative reviews associated with both models.

What Buyers Like

Positive feedback on the 59 MAX+ commonly centers around:

• Solid construction
• Easy operation
• Accurate readings when used correctly
• Useful laser targeting
• Wide temperature range
• Confidence associated with buying a Fluke instrument

One specialist test-equipment retailer has a five-star owner review from a customer who bought the 59 MAX+ as a replacement for an older infrared thermometer and specifically praised its operation and laser pointer.

Another retailer review database shows a much larger group of 59 MAX+ buyers with an average rating around the mid-four-star range. Positive comments repeatedly mention accuracy, sturdy construction, ease of operation and the wide -30°C to 500°C range.

Amazon-linked marketplace review data we found also showed the 59 MAX+ at approximately 4.3 stars across more than 200 customer ratings, with accuracy and solid construction among the recurring positives.

That is broadly consistent with what we would expect from the specifications. This is a fairly simple instrument, and when used on an appropriate target with the correct emissivity setting it should be straightforward to operate.

Complaints About the 59 MAX+

There are also some sharply negative comments.

Fluke’s own website currently has only a very small number of published customer reviews for the 59 MAX+, and both are negative.

One owner complained of a very large disagreement between the infrared reading and a probe measurement on a radiator.

Another disliked the instrument’s HOLD and automatic shutdown behavior.

Those complaints should not simply be ignored, but the sample size on Fluke’s own site is extremely small compared with marketplace review counts.

There is also an important distinction between an actual defective instrument and an infrared measurement that appears inaccurate.

Complaints About the 59 MAX

The regular 59 MAX has received similar criticism.

Some owners report units that stopped functioning, intermittent operation or measurements they believed were inaccurate.

Fluke’s own customer-review section currently has several such reports.

However, some of the measurement tests mentioned in negative reviews involve boiling water, ice water or human body temperature.

Those tests can be misleading when evaluating a general-purpose industrial infrared thermometer.

Why Some IR Thermometer Reviews Need Context

An IR thermometer measures surface temperature, not internal temperature.

It also does not measure a single mathematical point.

Several things can produce an unexpectedly high or low reading:

• Incorrect emissivity
• A shiny or reflective surface
• Standing too far from a small target
• Measuring steam instead of the intended surface
• Measuring through glass
• Reflections from nearby hot objects
• Trying to measure human body temperature
• Comparing surface temperature with a probe measuring internally

For example, pointing an infrared thermometer at boiling water is not necessarily a perfect calibration test. Steam and reflections can complicate the measurement, while a contact probe immersed in the liquid is measuring the water in a fundamentally different way.

Likewise, neither the 59 MAX nor 59 MAX+ is a medical thermometer. A forehead temperature reading should not be expected to correspond directly with body temperature.

This does not mean every negative review is user error. Reports of dead displays, intermittent electronics or other hardware failures are legitimate reliability concerns.

It does mean that complaints about IR measurement accuracy need to be evaluated in the context of what was being measured and how the measurement was performed.

Overall Customer Feedback

Our interpretation of the feedback is that both thermometers generally perform well when used for their intended purpose, but neither has a completely spotless customer-review history.

The 59 MAX+ has an advantage in its published specifications, but we would not buy it because online reviews suggest it is dramatically more reliable than the 59 MAX.

We would buy it because it has objectively better range, optics and accuracy specifications.

When the Fluke 59 MAX Makes More Sense

The regular 59 MAX still makes sense if you primarily work with:

• HVAC systems
• Refrigeration
• Household appliances
• Electrical equipment
• Motors and pumps
• Automotive cooling systems
• General workshop troubleshooting

Its 350°C maximum temperature already covers an enormous range of everyday work.

Its ±2% accuracy is also perfectly adequate for applications where your real goal is identifying a hot motor, comparing HVAC vents or finding an abnormal breaker rather than making laboratory-grade temperature measurements.

If the 59 MAX is substantially cheaper than the MAX+, it remains a sensible buy.

When the Fluke 59 MAX+ Is Worth Paying More For

The 59 MAX+ becomes particularly attractive if you work around:

• Automotive exhaust systems
• Furnaces
• Industrial heating systems
• High-temperature machinery
• Manufacturing equipment
• Hot process piping
• Ovens
• Heating elements

The higher 500°C limit is the obvious advantage in these applications.

However, you do not have to measure 400°C surfaces to benefit from the MAX+.

The improved 10:1 optics are useful at ordinary temperatures too.

So is the tighter ±1.5% accuracy specification.

These improvements apply to much more than just high-temperature work.

Is the 59 MAX+ Worth the Extra Money?

For us, the answer depends mostly on the price difference.

If the two thermometers are close in price, buy the 59 MAX+.

You get:

• 500°C instead of 350°C maximum temperature
• 10:1 instead of 8:1 optics
• ±1.5% instead of ±2% rated accuracy at 0°C and above
• Slightly better repeatability

And you give up essentially nothing.

The MAX+ uses the same AA battery, weighs the same amount, has the same basic dimensions and retains all the useful MIN/MAX/AVG/DIF and alarm functions.

If the MAX+ costs dramatically more and you know you will never measure above 350°C, the decision becomes less obvious.

For basic HVAC or home troubleshooting, the regular MAX will do nearly everything most users require.

Fluke 59 MAX Advantages

Choose the 59 MAX if:

• It is significantly cheaper
• You rarely measure above 350°C
• Most measurements are made reasonably close to the target
• ±2% specified accuracy is adequate
• You mainly need an IR thermometer for HVAC, electrical or household troubleshooting

It gives you essentially all of the MAX+’s convenience features without paying for capabilities you may never need.

Fluke 59 MAX+ Advantages

Choose the 59 MAX+ if:

• You may measure temperatures between 350°C and 500°C
• You want the better 10:1 optical ratio
• You want the tighter ±1.5% accuracy specification
• You measure smaller targets from farther away
• You work in automotive or industrial environments
• The price difference between the two models is relatively small

For professional use, these modest specification improvements can justify spending a little more.

Final Verdict

The Fluke 59 MAX+ is the better infrared thermometer, but the difference is evolutionary rather than dramatic.

Both models share the features that make the 59 MAX family useful: adjustable emissivity, a fast response, single-laser targeting, MIN/MAX/AVG/DIF modes, temperature alarms, a backlit display and convenient AA-battery operation.

The MAX+ improves the three specifications that matter most:

Temperature range: 500°C vs 350°C

Optics: 10:1 vs 8:1

Accuracy: ±1.5% vs ±2% at temperatures of 0°C and above

That makes the purchasing decision fairly simple.

Choose the Fluke 59 MAX if you primarily need a dependable general-purpose infrared thermometer and it is substantially cheaper.

Choose the Fluke 59 MAX+ if the prices are reasonably close, you expect to measure hotter surfaces, or you simply want the better-performing instrument.

For most buyers comparing the two directly, our pick is the Fluke 59 MAX+.