LACO Develops New technology to Match Customer Needs
We recently shipped a job for a client who needed a vacuum system for altitude testing, specifically to fulfill the requirements of ASTM Test D6653 “Standard Test Methods for Determining the Effects of High Altitude on Packaging Systems by Vacuum Method”. This test simulates the effects that a product would be subjected to in the cargo hold of an aircraft.
The unusual part of this test was the rate at which the pressure needed to be lowered and raised to simulate the climb and descent of aircraft. Usually, our clients prefer to pump a chamber down to a specified pressure level and vent back to atmosphere as rapidly as possible so each test cycle can be accomplished as quickly as possible. For ASTM D6653, the rate of pump down and the rate of return to atmospheric pressure is strictly regulated so our engineers got to play. And by play, we mean design a near PID (Proportional-Integral-Derivative) type controller that ramped pressure within the chamber up and down according to the ASTM-specified rate using a butterfly valve, a choke, our VC-3000 controller, and lots of hours of nerding out, programming the software.
They were able to develop an algorithm to carefully control pressure over time to precisely mimic the environment that products would experience when traveling by air (They did not, however, have to simulate a cavity search by the TSA). Kudos to LACO engineers! They may not be most adept at charades (unless its about Star Wars), but they sure know suck. The most impressive bit about this problem solving, has to be the data. ASTM allows a 20% variance either way in actual pressures, but a review of a test cycle showed variances of less than 1 percent either way. That even earns a 10 from the Romanian judge!
So if you have a vacuum problem that’s keeping you up at night, give us a call and we’ll sic our best number crunchers on it. They’re bound to find an answer that will work.