It’s a fact that air gages are typically not in use approximately 90% or more of the time they’re in your shop or QC department. Because these gages function through the use of clean and dry compressed air in a high controlled flow, this relatively expensive commodity can cost your operation unnecessarily, when not in use.
Now, it would be impractical and inefficient to turn off the unit when not in use, as doing so would require an extended period of time to restart, balance, and stabilize the measurement to achieve the desired accuracies. Since air gaging, by definition, requires the precise measurement of the air flow across the surface of the part being evaluated, this stabilization in the air flow is critical to running an efficient department and maintaining the proper protocol in your measuring procedures.
Imagine, however, that you could connect the air column to a digital I/O regulator switch, to turn down the air flow when the unit is not in use. Such technology is now available and it has substantial energy saving upsides for any operation. The air flow can be restricted by as much as 90%, but still flow at a consistent and measured level. By doing so, you can guarantee that the measurements taken when the air returns to full flow will be accurate and repeatable. Meanwhile, the energy savings you realize are substantial.
How to Implement
Such technology, to be optimally beneficial to your shop, must have the proper interface between the column and the power supply to function effectively. In one configuration, a proximity switch is positioned in the gage holder and the air flow can be triggered when the gage is removed from the holder.
Another means of arranging this type of controlled but not entirely restricted air flow is to use a pushbutton actuator on the face of the column control panel, or a foot pedal actuation could be possible. (Photos show air gage and air ring, plus installation illustrating the shutdown mechanism on the air compressor that reduces the air flow by 90% when the air gage is not in use, thus saving substantial energy costs for the shop.)
While it is difficult to calculate the exact cost savings to a shop, owing to the various factors of on-time utilization and local energy costs, the fact remains that, in most shops, air is blowing as much as 95% of the time without being used for gaging. If your compressors don’t need to run, in order to produce this unused air flow, the savings can be quite substantial. On average, a 40% or better savings in direct energy costs per compressor would not be unreasonable to expect.
If you’re using air gaging at the present time, talk to your supplier about auto-shutoff switching and other forms of actuation for a reduction of compressor use. Such equipment can also be configured to upload the data on actual on/off time via an Ethernet or Profibus cable with RS232 or RS485 serial interface for monitoring of the energy consumption, so the validation of such an investment is readily available to your operation. Also, on more sophisticated air columns, there would be no need for an external pressure regulator, as the column usually has such controls onboard.
