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The Best Micron Gauge 2021

Best Micron Gauge

A micron gauge is used to measure the levels of degassing and dehydration within air conditioning systems. Unlike a regular AC manifold gauge set, the micron vacuum gauge alternative uses a much higher resolution.

The best micron gauge is the Fieldpiece SMAN360, which works with 45 refrigerants and comes with an intuitive digital display for using all the features.

Thanks to the advancement in technology, micron gauges have seen a huge improvement in accuracy and usability. Most units are able to connect to a smartphone via a wireless connection for live data logging and reporting.

Table of Contents

Best Micron Gauge

Micron GaugeRefrigerant ProfilesManifold
Fieldpiece SMAN360703 Valves
Fieldpiece SM480V704 Valves
Testo 0563 1550603 Valves
Testo 552602 Valves
Appion AV760N/A1 Valve

Fieldpiece, Testo and Appion are the main brands that deal with micron vacuum gauges. They offer a range of units but the examples listed within this article are the best options to choose for beginners to professionals.

Micron gauges are versatile tools that are useful in both the automotive and commercial industry for tackling air conditioning issues.

Below is a list of the best micron gauge that will measure the exact level of degassing and dehydration with an intuitive digital display.

Fieldpiece SMAN360 3-Port Digital Micron Gauge

Fieldpiece are a major brand within the micron vacuum gauge industry and produce a range of devices. The S-MAN360 is a premium option that is designed for professionals with many features available to improve efficiency.

This model is able to instantly calculate superheat, which allows the user to avoid guesswork or manual calculations.

Other features of the Fieldpiece SMAN360 include:

  • 3 port design
  • Automatic targets superheat
  • 70 refrigerant profiles
  • Intuitive digital display
  • Alarm, stopwatch and rate indicator
  • Simultaneous superheat and supercooling
  • Includes a carrying case
  • Resolution from 50 to 9,999 microns
  • Weighs 4.9 LBS

Although it is one of the most expensive micron gauges in this article, the Fieldpiece SMAN360 is the best option. It works with 45 refrigerants and can be easily updated via the USB connection, which is beneficial for new refrigerants in the future.

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Fieldpiece SM480V Micron Vacuum Gauge

Another micron gauge by Fieldpiece is the cheaper SM480V model with the newly designed SMAN manifold. It uses a four valve manifold, which the brand claim is the toughest and most advanced design on the market.

In terms of the data logging, it is able to store up to 9 jobs internally, which can be easily downloaded via a USB connection.

Other features of the Fieldpiece SM480V include:

  • Heavy duty water and impact resistant casing
  • 70 refrigerant profiles
  • Strategically placed thermocouple ports
  • Advanced digital refrigerant manifold
  • 168 continuous hours of data can be logged
  • Tightness test check for leaks
  • Weighs 6.4 LBS

Overall, the Fieldpiece SM480V is an ideal tool for setting superheat and sub cooling in AC units and other commercial settings. It features many advanced functions and is cheaper than the professional SMAN360 model above.

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Testo 0563 1550 Digital Micron Gauge

The Testo 0563 1550 is another premium option that is not produced by the Fieldpiece brand. It has a total of 60 refrigerant profiles and added functionality for leak tests compared with previous models that they produced.

If you prefer to read from a smartphone, this micron vacuum gauge will do exactly that as well as communicating with Bluetooth smart probes.

Other features of the Testo 0563 1550 include:

  • 60 refrigerant profiles
  • Intuitive display and app integration
  • Metal frame around the device for durability
  • Two removable temperature clamp probes
  • Direct superheat and subcool readings
  • Includes a carrying case and batteries
  • Made in the USA

Although this Testo model has been on the market for many years, it is still very popular and used by professional on a daily basis. The Testo 0563 1550 also has 60 refrigerant profiles, which makes the micron gauge more versatile.

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Testo 0560 5522 Digital Vacuum Micron Gauge

Another micron gauge by Testo is the 552 model, which is the latest digital micro gauge that they produce. It is able to setup a wireless connection to communicate with smartphones via Bluetooth to provide analysis and reporting tasks.

The standout feature of the Testo 552 is the compact design with a polymer case. It packs a range of functionality into such a small device, which makes it highly portable.

Other features of the Testo 552 Micron Gauge include:

  • Precise vacuum measurement
  • 60 refrigerant profiles
  • Displays the saturation temperature of H2O
  • Easy to read backlit display with visual alarms
  • Wireless Bluetooth communication
  • Made in the USA

Overall, it is an excellent all-round micron gauge with an intuitive digital display and rugged design. The 552 model by Testo also offers excellent value for money when compared against many of the alternatives.

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Appion AV760 Digital Vacuum Gauge

The Appion AV760 is another compact micron gauge but unlike the Testo model, this comes with a premium price. It has a small digital display but connects to the dedicated smartphone application for remote, real time viewing.

In terms of the accuracy of this micron vacuum gauge, it has a full range response from 760,000 microns to just 1 micron.

Other features of the Appion AV760 include:

  • Water resistant housing rated at IP65
  • Simultaneous measurement
  • Live data logging and reporting
  • Filter and oil catch to keep sensors clean
  • NIST-traceable certification
  • 6 different units of measurements
  • Lightweight at just 1.1 LBS

Although it is an expensive alternative to the above micron gauges, it does provide precision measurements and is built by a reputable brand. It also has the unique benefit of being water resistant with a rating of IP65.

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Micron Gauge Buying Guide

The purpose of a micron gauge is to read and analyze the level of the atmosphere. You can also determine levels of dehydration and degassing within the system, which will produce alarms upon the gauge if they have reach damaging levels.

These devices are used within the automotive and commercial industry. They are mostly used by garages or professionals that carry out diagnostics upon air conditioning systems on a daily basis.

To help you make an informed buying decision, we have produced the below guide regarding micron gauges.

best digital micron gauge

Digital Display

The use of a digital LCD display is far more desirable than the older analog alternatives. They are clearer to read with bigger fonts or numbers and most will allow you to switch between the different units easily.

Smartphone Communication

The benefit of upgrading to a modern micron gauge is that they provide smartphone communication. This is made possible by downloading the brand specific application and using Bluetooth to connect with the device.

Once the connection is successful, you will be able to view real time data logging, store data and many more functions.

Manifold Design

Depending upon the application, you may require multiple valves to diagnose a system. Most premium options include multiple valves for tackling most systems. They may also include valves that have been strategically placed for connecting to the ports from all angles. The Fieldpiece SM480V is a great example with 4 valves at different angles.

Refrigerant Profiles

To ensure that the micron gauge is as versatile as it can possibly be, you will want plenty of pre-programmed refrigerant profiles.

However, as many manufacturers are switching the refrigerant used, you will want a method of updating the device. Most premium options will allow you to do this via a USB connection or by the smartphone application.

Precise Accuracy

Accuracy is a key performance indicator to the quality of the micron vacuum gauge. To ensure that the stated accuracy specification is reliable, you can check whether the unit has been awarded a NIST Calibration certificate. Accuracy is measured in microns with premium gauges such as the Appion AV760 able to provide a full range response between 760,000 microns to just 1 micron.

best micron vacuum gauge

Design and Durability

As with any tool that is used within a garage or commercial application, durability is an important factor. Most micron gauges have a rugged construction that can withstand impact damage. However, not every device is water resistant with some offering a higher IP rating than others.

Depending upon where you plan to store the device, the design and size may be an issue. Smaller units are ideal for storage and offer great portability qualities but may lack certain features and additional manifold valves.

Maintenance of the Gauge

Dirt can cause issues with the performance of the micron gauge and you will want to clean the gauge whenever possible. There are many methods and cleaning solutions to use, which take just a few minutes.

Moisture vs System Leak

Many people will invest into a micron gauge for diagnosing whether the system has moisture present or there is a leak. If the system has moisture, the gauge will respond with a much higher reading as oil is trapped within the moisture. It will then continue to rise until the the vapor pressure equalizes inside the system.

If there is a system leak, the micron gauge will rise until the atmospheric pressure has been reached. Whereas moisture inside the system can be solved by an evacuation, a system leak will often need replacement parts as well as an evacuation.


Investing into a quality micron gauge is a worthwhile investment as most will be long lasting and have the ability to be updated.

We highly recommend the Fieldpiece, Testo and Appion brands as they have been producing high quality HVAC products for many years. Each brand also provide plenty of replacement parts, which helps you keep your unit running smoothly.

All of our recommendations are suited to a range of budgets and skill levels. Cheaper alternatives may be tempting but our recommendations are the best units on the market that will not disappoint.

procarreviews author

Written By Dan

About the Author

Dan is an automotive journalist and owner of over 10 cars ranging from supercars, tuned cars, classics and your good old beater cars. He always likes to get his hands dirty with nut and bolt restorations or detailing sessions using the best products on the market.

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