When it comes to choosing an air gage, you have two main options: single master or dual master. While they each come with their own benefits, there is no one better option and the perfect choice will depend on your needs. In this article, we give you a brief overview of the differences between single and dual master air gage systems as well as a more in-depth look into dual master systems and their benefits.
How Single Master Air Gage Systems Work
Although single master systems tend to be costlier, this is because they have to be manufactured to the highest standards in order to ensure accuracy. As accuracy is built into both the display and air tooling, linearity is known throughout the entire range and they are fixed to work only with tooling that is compatible pneumatically. This enables users to set the air gage to a pneumatic zero for comparative measurements without the need to adjust magnification.
This fixed magnification system means that a specific amplifier is needed for each individual tool, and additional tools are required to verify system calibration. This all adds up to a higher cost. However, the plus is that single master air gage systems provide excellent stability, not being susceptible to small changes in pressure.
Building A Dual Master Air Gage System
An alternative to single master systems is the dual master system. As the name implies, dual master air gaging systems make use of two masters when setting the pneumatic range as opposed to being made to fixed characteristics. The tooling and display systems are set by the user to ensure that the span matches that of the minimum and maximum masters.
When a dual master system is used, the responsivity of all components within the system are set simultaneously, which goes a long way in ensuring that all the different parts work together to display master values accurately. These parts include the air hoses, air flow restrictors, air jet nozzles and more.
The Problem with Manual Knobs on Dual Master Systems
Dual master systems are built around a back pressure system that is adjustable, where a display monitors the change in pressure. This occurs when the air jet nears the surface it is supposed to measure and encounters restriction. This system consists of two user controls – one for zero and one for span – which are responsible for adjusting the span, which will then be displayed on the masters.
The problem with older dual master systems is that these controls have to be adjusted concurrently in order to achieve the required span. As these controls respond to each other instead of working individually, getting the precise span can prove to be a task. While this is not a problem for experienced users, for whom this process has become natural, it can take new users a lot of time and effort to get it just right.
Electronic Dual Master Air Gage Systems
With the introduction of new technology came about electronic dual master air gage systems. While some still make use of the two-control system to achieve the desired span, many newer models have eliminated the use of manual controls. These models make use of the air transducer to determine the range, with the user keying in the minimum and maximum master values on the display.
However, similar to single master systems, dual master systems come with their own benefits and unique applications. The largest selling point is that they can be used with a wider range of air tooling due to the adjustable magnification, although it is possible for linearity to suffer under certain circumstances. In addition, they can be used with extremely small and extremely large jets, which allows for both short range and long range as well as high and low tolerance applications. These systems are also easy to clean and maintain due to the higher air pressure which cleans coolants and oils from the part.
Choosing between a single or dual master air gage system largely depends on the unique needs of your industry. While they both come with their benefits, there is no single best system, only the one that will suit you better.