Our typical compressed air system audit lasts for 1 week, 168 hours or 10,080 seconds. We install data loggers for pressure, flow, amps and voltage. We perform a full plant walkthrough, an examination of all applications that use compressed air, and we also perform an ultrasonic leak audit.
All of this logging produces a lot of data. Since our equipment records in seconds, 10,080 lines of data is produced for each item that is data logged. All of this information can be graphed and charted. For those of us who analyze the data, these graphs and charts can prove invaluable, allowing us to assess systems in microscopic detail. Our audit software has 19 graph formats, and each of these 19 graphs can be produced for the week or by the day, creating 133 graphs. We also have 12 chart formats that can be produced for the week, or by the day, creating 84 charts.
We are often invited to explain compressed air audits prepared by other auditors where every possible graph and chart has been used, printed and delivered to a customer with a single paragraph telling the customer that all they need to do is buy a new variable speed drive air compressor to solve their compressed air system problems.
When we produce audit reports however, we only use 2 or 3 graphs, and 2 or 3 charts, with salient points that help us tell a story. We have already combed through the audit results and made our assessment - now we need to communicate that information in the simplest and easiest way, and so we describe what we saw and why it was important.
If a graph helps us illustrate a specific point of concern then we will include it, but our strongest audit tool is our observations, without these all of the charts and graphs have no perspective. The average person looking at an air compressor profile graph might recognize the signature of a compressor short cycling, but without an explanation based on a visual observation, this detail might just be lost in another pile of useless graphs.
The best compressed air auditors spend more time outside the compressor room understanding the purpose of the compressed air, and how it affects or impacts the processes it is there to support – this is what should be most important to every client, not the auditor who provides the most graphs.