CMS levels in your sieve beds should be measured every 18-24 months to check for loss of material and settling.  Symptoms of a loss in CMS material include purity not in spec, as well as CMS “dusting” in the process valves and downstream filtration.To check CMS levels:Turn your unit off.Valve your N2 storage tank by closing the valve coming from the generator.Depressurize your sieve beds by opening the ball valves located on the front of the unit (each side).They have yellow handles and have a pressure gauge located next to them.  These will stay open for the entirety of this process.  Smaller units will not have valves and pressure can be released by pulling up on the safety relief valve on the top of the bed.Remove the plugs on the very top of the sieve beds.Measure from the top of the threads until your tape measure stops.Anything over 7 inches is open void and needs to be topped off.  Please Contact Us to get a quote for additional CMS material.