Now here is a particularly ugly site. Let's make a guess that the manufacturer claimed NIST traceability when it shipped this gas. But MSA doesn't make calibration gas. They buy it and resell like all the other gas detector manufacturers. MSA is a great company, but they are calibration gas re-sellers.
So we start with the original calibration gas manufacturers claiming NIST traceability (we've already discussed that), next the gas detector manufacturer resells the product and claims the same when they sell it to their distributor who claims yet the same traceability. Then their distributor sells it to a customer and finally that enterprising customer puts the half-used calibration gas cylinder up for sale on eBay where yet another customer buys it to use to calibrate their gas monitor.
Is the calibration gas still NIST traceable? How many re-sellers can this poor calibration gas be re-sold to and still claim traceability? In fact, is it maybe past the point of expiration? The expiration date is right on the cylinder, but the way the eBay picture is displayed you can't see the product expiration date. Take a look at the cylinder and tell me what you think.
And was it contaminated during use? Did toxic sludge get smeared inside the valve? How would you know? Seriously.
Here's a real life scenariuo for you- one of my customers brought me a 58 liter cylinder to vent, vacuum, purge and de-valve for recycling. It was half full. Had the usual accuracy and traceability claims on the label. But when I took out the valve and looked into the cylinder I saw an eighth of an inch of water.
That's right, water in the bottom of the cylinder. The mixture was SO2/ balance nitrogen. What do you think happens to 25 ppm SO2 when there is water in the cylinder?
Maybe instead of recycling it I should have just put it up for sale on eBay. Yeah, that's the ticket.