Compressor Air Gages (Gauges)

Compressor Air Gages
(Last Updated On: August 21, 2019)

How to replace an air gauge, you say? Well the nature of the compressor air gauge that likely comes along with a low-cost DIY type air compressor,  and they are just that…low cost. Both the compressor and the air gauge… cheap!

This means that the gauges are not built to handle heavy, prolonged use which might break a gauge needle,  and they will fail due to internal corrosion or mechanical fatigue. That might take months or years, depending on the use and the condition of the compressed air the gauge is monitoring.

Further, for many of us, our air compressors are relegated to the basement or workshop where things pile on them, other things run into them, and ultimately the gauge face gets cracked or the entire gauge might get broken off.

Time to replace your air gauge? It is pretty easy. Here is how.

There Are Two

First, know that most DIY type air compressors come with two gauges. One of the gauges is to give you a reading of the air pressure in the compressor air tank.

The other gauge is normally found as part of the regulator assembly on the discharge line from the tank to the outlet coupling. This gauge is to show you the pressure setting on the regulator, and shows the air pressure for your downstream application.

 

Top 3 Air Compressor Gauges and Effects of Climate on Your Tires’ Pressure

If you have used air compressor gauges before, you likely fully agree with me that the measurements that these devices show can mean the difference between a safe journey and a disastrous one. The fact is that you should have the right amount of pressure in your tires at all times. And, since people lack the natural ability to determine it, you need a compressor gauge to make your life easy and protect your tires and your rims. Furthermore, remember that if you buy this simple device, you will not need to go to your dealer whenever you are doubtful of your tire’s pressure. Here we have compiled for you some of the best gauges that are significantly helping smart drivers to avoid unwarranted headaches and costs.

1. Rhino Heavy Duty Gauge – For Highly Accurate Measurements in all Situations

Are you looking for an air compressor gauge that will give you the best value? Rhino heavy-duty gauge might be what you are seeking. Most of the users of this easy-to-use device say they love its high quality and affordability. Other than that, they are pleased that it has a manual dialogue gauge and efficiently operates without a battery, which guarantees them highly accurate measurements. If you want such a high degree of accuracy and convenience, choose this device.

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What’s more, this Rhino gauge will likely give you exceptional flexibility at all times. It is a 75PSI tire pressure gauge. That means you can read from zero up to 75 PSI. Additionally, the glowing in the dark feature makes it easy to find this device in the dark. Besides, with the well-lit LCD, you will be able to check the readings in the night without any problems. The bendable hose that is included in the package also enhances its usability. But if you are concerned about the device’s safety, most experts will tell you to think about its ergonomic design. That ideally ensures you can firmly and comfortably hold the gauge while you use it.

Specification

Brand:  Rhino USA

Model:  BEST-75PSI-TIRE-PRESSURE-GAUGE

Weight:  8.2 ounces

Pros

  • Manual dial gauge ensures accurate readings
  • Features an ergonomic design to enhance safety
  • Rhino provides a lifetime warranty
  • Well-lit LCD ensure high visibility
  • Highly Affordable
  • Best for any car

Cons

  • The long bendable hose can be unuseful
  • Relatively heavy

2. Tekton Digital Air Gauge for the Best Digital Budget

Tekton complies with all tire nozzle requirements, and that is one of the reasons it has received positive reviews from many users as well as car fans. Many are also intrigued by its numerous amazing functions and quality and consider the price stag favorable.

One of these great features that you cannot ignore is its digital display that convectively shows you the pressure of your car with 2-3 seconds. Other than that, you will not have to worry about the lighting system of your garage. The digital display produces enough light to enable users to see their tire pressure with incredible ease.

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 The manufacturer did excellent work with the design as well. This gauge possibly features among the top solutions partly because it is ergonomically designed. You will retain an excellent grip over it at all times. Its strong nozzle seal also reduces the air the amount of air that gets into the nozzle. And, in case your gauge goes into a sleep mode, you can put a little pressure on the provided push button to awake it. While Tekton digital air gauge uses a battery, you do not need to worry much about the inconvenience. The batteries can last for at least one year.

Specifications

Brand:  TEKTON

Model:   5941

Weight:  3.2 ounces

Pros

  • Lighted nozzle and display screen ensures perfect visibility at all times
  • Digital display instantly and indicates accurate readings
  • Simple push-button perfectly controls the device
  • Ergonomic design securely fits hands

Cons

  • Battery cost

3. Accutire MS for a Fully Controlled Inflation

Accutire MS comes with an easy to read LCD that provides accurate pressure readings from as low as 5 to as high as 150 PSI in 0.5-pound increments. This will prevent you from squinting to make out the readings when the weather is dull or at night.

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More, this model has a user-friendly interface and features rubbing coating for stability as a well a good grip. That is not all that you should anticipate. It also features an automatic shut-off feature that ensures tires achieve only the designated pressure during the inflation process.

Specifications

Brand:  Accutire

Model:   MS-4021B

Weight:  0.64 ounces

Pros

  • Offers highly accurate measurements
  • Bright LCD increases convenience
  • Angle head and rubber-coated handle ensures easy gripping
  • Automatic shut-off feature guarantees adequate inflation
  • Replaceable battery

Cons

  • Battery cost

 

Does Climate Influence the Pressure of Tires?

Before you buy any gauge, know the climate of your area because you need a device that can serve you irrespective of where you are. Remember, extreme temperature shifts will always significantly affect your tire pressure. For example, during winter, the cold will reduce the amount of oxygen in the air and constrict the air in your tire. The opposite will always happen during the summer.

If you are driving from a hot to a cold region, you will need your gauge to ensure your car maintains the right amount of pressure throughout your journey.

If you are traveling in the winter, you may need to have a set of snow tires. And, more importantly, you will need a reliable air compressor gauge. Remember, just as we have said, any extreme variations in temperature will affect your tire pressures. If you buy a high-quality gauge, you will be able to know you exactly need to either inflate or deflate your tires.

When you are driving, you are actually gliding on air and your safety matters a lot. As you can see, a good tire gauge is a difference between a safe and convenient journey and a costly and disastrous one. No matter what people think about this subject, the truth is that there is no better way we can ensure our tires have the right pressure than buying and using efficient compressor gauges. If you have problems identifying the correct tire gauges for you, we have provided the three best options from around the Internet that we have seen above. Choose the one that perfectly meets your unique needs, and you will lead a peaceful life and protect your car.

 

Air Gauge Configurations

Compressed air pressure gauge - understanding-air-compressors.com
Typical air pressure gauge. Photo: Northern Tool

As depicted in the photo the air gauge has a face on which the pressure range for that gauge is visible. That scale is protected by a carbonate or glass face, which is susceptible to breakage.

The diameter of the standard air gauge face is 1 1/2”. Another air gauge standard diameter is 2”. Yours is likely one or the other, and I would lean to the 1 1/2″ size as being typical, as it costs the manufacturer less money to install a smaller gauge on an air compressor.

The gauge will be equipped with a male thread fitting on the bottom or the center of the back. It does not matter to the gauge whether it is turned into  the air line from a male thread on the bottom of the gauge, or a back located male thread.

The different locations of the mounting threads are purely for the convenience of the installer or the location of the air line into which the gauge is threaded.

You can also purchase air gauges that are panel mounted to facilitate an industrial type installation. A panel mount gauge typically has a back mount, and comes with a space ring that allows the gauge to fit into a through hole on the panel, without dropping completely  through. An installer may have to run an air line to the back of the panel mounted air gauge.

 

Air Gauge Pressure Ranges

The typical DIY type compressor air gauge will have a pressure range of 0-160, maybe 0 to180 or even 0-200 PSI.

Air Gauge Pressure Ranges

As long as the air gauge you obtain as a replacement shows the normal cut in pressure level of your compressor, and the normal cut out pressure level, that it is a 180 PSI versus a 200 PSI really makes no difference.

Specialty application gauges will have different pressure scales on them, depending on the application for that gauge.

 

How To Buy Compressor Gauges

If your old gauge is in good shape  (or even if it is not) take it with you to the shop so that you can match-the-hatch and get the same size fitting, same sized face, and same pressure range.

If your new gauge is a back mount type, and your existing gauge has the fitting on the bottom, the new gauge may not fit. It is always good to get the same size and style if at all possible.

If your air gauge is totally gone, opt for a 1 1/2” face, 0-200 PSI pressure range, with a 1/4” male NPT fitting on the bottom. That is a pretty good fit for many DIY type air compressors.

 

How Much Are Compressor Gauges?

The new gauge will set you back somewhere between $5-$15 or so, depending on where you buy it.

If the gauge is priced more than that, it is possible you are buying:

  • a) an overpriced air gauge
  • b) a much better quality air gauge than needed
  • c) a specialty gauge of some sort
  • d) a different compressed air component entirely 🙂

How To Setup A Guage On A Compressor?

Make sure you unplug your compressor and open the drain valve in the tank to empty the air pressure completely. Else, when your air gauge gets down to the last thread, one final turn will shoot that sucker right up and out of your hands, as the air pressure in your tank blasts to atmosphere. Be careful!

Some gauges have wrench flats to use a wrench, some rely on you turning the body of the gauge to unscrew the thread. If the gauge is not broken before you do this, it quite likely will be after you do so!

compressor gauge

Anyway, unscrew the old gauge after you double check that there is no air in the compressor tank.

Use pipe dope or teflon tape (better the former than the latter as far as I am concerned) to coat the threads on the new gauge.

Turn the new gauge into the compressor boss until snugly-hand tight, and then turn if just further enough to orient the air gauge face to where you can best see it.

No need to over-tighten, as the pipe dope will seal the threads if they are screwed in just past hand tight and if you tighten too much, the gauge may break.

Plug in your compressor (after you have closed the tank drain valve) and away you go. You might want to put some soapy water around where the gauge threads go into the compressor just to satisfy you that the gauge fitting is not leaking.

Which Air Compressor Guage Should I Buy?

Out of different pressure gauges which one can be used on my air compressor?

A visit to the big box store or hardware store may reveal a host of pressure gauges, or not, depending on the store. Which one(s) then are the right air gauges for the typical do it yourself home or small workshop air compressor?

It is necessary to actually look at the face of the gauge you are considering buying, looking at whether the threaded part comes out the bottom or the back, and the size of the male thread fitting on the gauge.

Wika air gauge - what air gauge and I use on my air compressor?
Photo: www.wika.ca/

It doesn’t typically matter if the gauge is a 1  1/2″ diameter face, a 2″ face diameter or a different size gauge face entirely, yet buying the replacement gauge that is the same size as the one that you are replacing on your air compressor helps ensure that it will fit in the same space on that compressor.

Some gauges are used to display vacuum. Some are built to display extremely low pressure, or a limited pressure range. Some are liquid filled. Some are made with stainless steel parts which has an impact on cost.

It is important to consider your compressor air gauge specifics when heading for the shop to buy a replacement air gauge. One day you may have to for if you have your air compressor long enough, yes, the air gauges do wear / rust out.

Here are the things you want to look for when selecting a replacement air pressure, or air regulator pressure gauge for your air compressor.

  • same size gauge face ( if possible, not critical if a larger / smaller air gauge face will fit the space on your compressor)
  • same (or close) pressure range displayed on the gauge face (close means within 10 PSI of the range of the existing gauge)
  • same size mounting thread or style (as in a male as opposed to a female thread, and the same NPT or Metric thread size)
  • same mounting position of the threaded fitting (whether the threaded part comes out the back or the bottom of the air gauge)

For a DIY type home air compressor, another indication that you have selected the right gauge will be the price. Expect to pay under $15 for a typical air pressure gauge for use in a general purpose, low cost air compressor. You can spend more if you wish. For example, buy a stainless steel gauge versus a cheaper “just metal” one. It will still work just fine all of the other issues noted above are the same, you’ll just spend a whole lot more for a stainless steel versus a basic gauge.

The same for buying a liquid filled gauge versus a basic gauge. The liquid filled gauge will work just fine, but cost a gazillion dollars more (comparatively speaking) than the basic gauge… and both will work.

Replacement compressor air gauges are available at most decent hardware stores, bit box stores, on line, and certainly should be available in the air parts section of the store from which you purchased your air compressor originally.

 

What Happens If My Air Gauge Fails?

When I’m using my at-home compressor, doing an odd job around the house, the needle in the air gauge may move a few hundred times a day as the air pressure fluctuates through compressed air use and the compressor cycling. This is low cycle rate for an air gauge.

Compare that to the air gauge on a system, perhaps containing dozens of air cylinders or air tools, all cycling at a high rate of speed 24/7/365. The mechanical components in the air gauge may cycle hundreds of thousands of times a day.

broken air compresssor gauge

Eventually, mechanical fatigue will cause the moving parts of the gauge to fail.

You can lengthen the functioning life of an air gauge in high speed circuits by using a liquid filled gauge.  Normally filled with glycerine, the viscosity(liquid thickness) of the filling tends to slow by a small degree the speed with which the gauge’s internal mechanical parts  and the needle moves with air changes, reducing mechanical wear and impact damage as the internal parts of the gauge return to zero when the air is repeatedly exhausted.

If you have an application where compressed air gauge failure occurs, consider using a liquid filled unit to extend the life of your compressed air gauge.

 

Air Compressor Gauges and PSI

Ever wonder why, if the ambient air pressure is one atmosphere, or 14.7 PSI,  the air gauge on an air compressor show zero when the air tank is empty instead of the 14.7 PSI ambient air pressure? The reason that your air gage doesn’t is that most compressed air gages are calibrated to read “0” PSI when the surrounding air pressure is actually 14.7 PSI.

This is to allow you to have an accurate reading of the changing air pressure in the tank or compressed air system, without having to add or subtract 14.7 PSI to allow for atmospheric pressure each time you want to know what the air pressure in your system is. When people talk about compressed air pressure then, they normally use “gage air pressure”, meaning that they ignore the 14.7 PSI of the atmosphere surrounding them.

air copmpressor gauge psi

For folks that want to have one (scientists, for example), you purchase air gauges that show the actual air pressure, and therefore, when your compressor tank is empty, that gage would show around 14.7 PSI, depending on the temperature, the humidity, and where you were in relation to sea level.

The air gage that comes with the DIY type air compressor will normally be a fairly low cost, low accuracy, general purpose air gage. The pressure reading (scales) of the general purpose gage will vary depending on the application for which that gage is intended. Common pressure ranges are from 0 PSI through to 160 PSI and sometimes higher, as is shown on the gage in the in photo above.

As you can see, this gage has a pressure range of 0 – 200 PSI, and also provides the user with pressure readings up to 14 bar. A single bar is 14.7 PSI, so 14 bar is approximately equivalent to 200 PSI.

The wider the scale (broader the range of air pressure) shown on the gage dial, the less accurate a reading the general purpose gage will provide. Typical general purpose air gages will provide a pressure reading that’s within 2-4 PSI accuracy of the actual air pressure in the system, an accuracy that is more than adequate for most home workshop compressor use.

If you desire to have a more accurate reading, you can purchase an air gage that has a much narrower range. 0-15 PSI for example, or 0-30 PSI, or 0-60 PSI and so on. The greater the need to have accurate gage pressure the narrower the range of pressure that gage should handle. You can also purchase air gages that are used for vacuum, and their reading will show a range of 0 PSI to -14.7 PSI.  Minus 14.7 ,(again, depending on the ambient environment) if the vacuum device can achieve that, is perfect vacuum.

Air gages commonly have an male NPT air fitting either located on the bottom, or the gage may have the male NPT fitting centered in the back as does the air gage in the photo above. Where you want the air gage installed on your compressed air system will dictate where the fitting will be for the air gage you acquire.

For most DIY and general purpose uses the gage that accompanies the DIY compressor will be adequate for a while. They tend to be manufactured of inferior quality components, and they will, in time, corrode internally to the point where the gage fails. In higher cycle applications, sometimes the needle will actually fatigue to the point where the needle breaks.

To overcome corrosion, it is possible to purchase air gages that are made completely of stainless steel, except for the glass, of course. The cost is prohibitive for most DIY applications. Where needle breaking is a problem due to high speed cycling of the air application, liquid filled gages solve that problem. The liquid in the gage (I believe glycerin or glycol) acts as a shock absorber or damper to slow down the needle movement, reducing impact and fatigue on the needle and imparting longer life due to that reduced metal fatigue.

Where it’s necessary to have greater accuracy in the air pressure reading, you can purchase Precision Gages that give you greater pressure-reading accuracy.

When searching for a replacement gage, here are the things to look for.

  • what is the range of the pressure reading of the gage you are replacing, or the range desired
  • what type of mount is it (back or bottom)
  • what size is that mount (usually 1/8 or 1/4  NPT

Have a question about a replacement air gauge. Help yourself to the comment box below.

 

 

How come there are two air gauges on my compressor?

A readers asks this question. “How come I have two air gauges on my compressor… wouldn’t one be enough?”

A valid question, with a fairly simple answer.

One of the air gauges is to indicate the pressure that is in the compressor air tank. As the compressor runs up to cut out pressure, and the compressor stops, isn’t it good to know what pressure is in the tank? This also confirms that the system is working, and the pressure switch shut the compressor off at the right pressure setting.

two air gauges on my compressor

The other air gauge is normally plumbed or installed on the regulator, which is downstream from the first gauge, and this ones purpose is to show the setting of the air regulator. The regulator setting indicates the pressure that the downstream compressed air using air tools or applications will get from through that regulator, regardless of what is shown on the tank gauge, and as long as the pressure in the tank is higher than the regulator setting.

Hello, I am Bill, the Compressed-Air-Man. I have years of experience in industrial and residential compressed air applications, air compressors and general pneumatics. I created this site to help professionals, students, and DIYers understand and properly implement and maintain compress3ed air systems.

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