Air to Electronic Gages and Sheffield Products


Radial Play GageWe manufacture and supply off-the-shelf and custom air gages, air to electronic gages, fixed gages and masters for a wide variety of manufacturing, machining and QC lab applications, including the renowned Precisionaire® series of the Sheffield gaging instruments.

        • Micronaire® air gages
        • Precisionaire® air gages
        • Attribute gages
        • Standard masters
        • Electronic gaging cartidges
        • Radial play gages
        • Air gage tooling & accessories

Sheffield Precisionaire Gaging


The Sheffield Precisionaire® Column from Precision Gage & Tool is the industry’s most accurate, dependable, and widely accepted air gage instrument. While its truly modular design is adapted to the same proven principles used for air to electronic gages for many years, today’s models are improved and simplified for increased reliability and operator convenience.


Modular gage design means that complete instruments in any combination of columns and amplifications can be assembled in minutes. Amplification is entirely pneumatic and linear over the full scale. Amplifications from 62.5 to 1 up to 40,000 to 1 are available. The graduated scales enable maximum and minimum tolerance limits to be set to allow plenty of “come-up” and “go-beyond” for accurate, easy reading.

Dramatically lower costs

With dependable air to electronic gages, scrap is reduced, no usable parts are rejected—and many out-of-tolerance parts are salvageable. Because inspection time is shortened, overall production time is reduced and machining processes can be brought under control more quickly. In many cases, costly high-skill man hours can be better utilized, as air and air to electronic gages requires a minimum of operator training and skill. Finally, air gauge size-sensing elements outlast conventional limit-type gauges many times, and, unlike many ordinary gauging methods, air to electronic gages allow easy compensation for gauge wear.

Less Time, Greater Accuracy

All air to electronic gages and air gage systems using Precisionaire Instruments can accurately inspect up to 40 or more part dimensions in the same time it takes to check one dimension with a conventional gauge. Side-by-side columns form a “float graph” which can be viewed instantly. Conditions and relationships such as average diameter, camber, squareness and other measurements which are extremely difficult to check are readily measured by Precisionaire systems.

Principles of Operation

The Precisionaire Column Instrument is essentially an air flow indicator. Pressurized air suspends a float in a transparent tube; this float moves up and down in the tube according to the flow of air. From the top of the tube, the air flows through a hose and exhausts through the clearance between the gaging device and the workpiece. The rate of air flow is proportional to the clearance, which is indicated directly by the position of the float in the column. Precise amplification and linearity are permanently built-in; the only moving part is the float supported on a column of air. The easy-to-read scale shows size at a glance.


Appropriate setting masters are used to establish the upper and lower limits of float travel in the column. These represent minimum and maximum part tolerance limits. Proper float travel between these limits are regulated by the external float positioning and calibration adjustments.

Internal or External Measurement

A typical gaging spindle has a central air passage and diametrically opposed air jets. It gauges the true diameter of a hole based on the amount of clearance between the spindle and part inside diameter (I.D.); any change in air flow is directly indicated as a dimension by the float’s position in the glass tube relative to the instrument’s scale.

In the case of internal diameters, master setting rings have internal diameters equivalent to the minimum and maximum part tolerance limits and are used for calibration. For external checking, Airsnaps or Air Rings, with opposed jets, gage the part to indicate dimensional size. Master setting discs with external diameters equivalent to minimum and maximum part tolerance limits are used for calibration.

Single or Multi-column Flexibility

Modular Precisionaire Instruments can be adapted as desired for single or multiple, internal and external dimensional measuring. This modular “building block” design enables small, as well as, large shops to meet on-the-job inspection requirements with flexibility, speed, and economy. The modular columns and base panels can be stocked in the tool crib, ready to assemble quickly for immediate use.

Precisionaire Column Instruments can be used with all existing or new standard and special tooling without alteration. Standard 9” models are available in amplifications of 1,000, 2,000, 5,000, 10,000, 20,000 and 40,000 to 1; standard 15” models are available only in amplifications of 5,000 and 10,000 to 1. Conversion kits can be supplied for quick change to any standard amplification.

Conversion Kit

Convert modular Precisionaire Column Instruments from one amplification to another in minutes. The Precisionaire Conversion Kit contains everything you need, including column seals, float bumper assemblies, float, glass tube and appropriate scales. Kits are available for the following amplifications: 1000 • 2000 • 5000 • 10,000 • 20,000 • 40,000.

Air Gage Tooling & Accessories

A complete selection of standard spindles: openjet and balljet, thru and blind type, steel, chrome and titanium nitride coated are available in sizes from .125 thru 4.000 diameters. Standard thru type, steel and chrome-plated airings range in size from .240 thru 6.010 diameters. Standard fixed “C” type airsnaps in sizes from .500 thru 4.500 are available.

Standard Masters
A full compliment of A.G.D. Standard master rings & disks, both steel and chrome, class X and XX are available along with other special masters for the calibration of standard products.

Electronic Gaging Cartridges
A full line of linear variable differential transducers (LVDT’S) features standard long, threaded, standard short, and right angle units, in various ranges and with choices of gaging tips.

P-400 Metrology Display

P-400 DRO Front ViewThe P-400 DRO is an advanced metrology display—and much more. Combined with an air/electronic converter and air gage tooling or LVDTs from Precision Gage & Tool, it’s a high-accuracy, economical gaging instrument ideal for applications requiring up to eight discrete inputs.

With intuitive visual displays, helpful audio cues and user-defined formulas, the P-400 DRO reports dynamic min/max measurements, provides SPC analysis from an integrated database and includes connectivity to PCs and other peripherals.

Get visual feedback from an easy-to-read, familiar interface with standard color cues and a choice of graphical formats, including bar diagrams, histograms and dial indicators. The P-400 instantly informs operators of pass/fail performance details for critical part dimensions. USB and RS-232 connectivity allows users to share data throughout quality and process control systems, and provides program storage capability.

Custom & Specialty Gages

Paper Gages

The smoothness and porosity of paper and similar materials can be easily checked with Sheffield’s smoothness and porosimeter gages.

Radial Play Gages

Sheffield Radial Internal Clearance gages are the industry standard. Simplified adjustments speed the change-over from one bearing to another. Models for bore sizes between 8mm and 318mm.

Fiber Gages

Micronaire® air gage instruments, both portable and with separate fiber compression chamber, are standard for the inspection of cotton, wool, fiberglass and similar materials

Flatness Gages

Stone flatness gages in four different sizes can be furnished for use with the P-400 DRO Metrology Display.