difference between Devilbiss mc-84 and mc-4490

[kismet]

I've narrowed it down to these two models. What is the difference between the two? Any info would be much appreciated.

[kbinkster]

Basically, the MC 84 is just the newer model that came after the 4490. It comes with the OCI standard (the little oxygen concentration indicator). Some of the MC 4490s have the OCI, but most don't.

However, for lampworking, we do not need the OCI. The OCI alarms at 90% +/- 3%. This means that it might not alarm until the purity has dropped down to 87%, which would already be too low for our purposes (we want 90% or better purity, not 90% +/-3%).

[Justin L]

The MC-84 has a little bit bigger compressor, and Bigger sieve beds. It also comes with the Oxygen Purity monitor as Kim stated. Its a newer variant of the MC 44-90. Because of the compressor and bigger sieve beds, it tends to put out a little better purity at the higher flow rates. Its still the same 5LPM and ~9PSI too.

The Low Oxygen light should come on at 86% purity and lower, since 87% and up is considered acceptable for medical purposes. If it comes on at 87% or higher, then something isnt right. I would say the OCI Circuitry would need to be calibrated. I have seen this problem once, so I wouldnt worry about that too much.

Im sure either one would work.