Low pressure use means it was set up for use with a low pressure manifold. In an industrial setting often places will get "gas" in bulk. Some times this is a bunch of gas cylinders all hooked up together as a bank and connected to a regulator that drops the high pressure gas down to a lower intermediate pressure, where it is then adjusted at the individual machine. Other times it can come in as a dewar in liquid form, then it is "boiled" off and the resulting gas flows to the machines. I can't remember if gas from a dewar needs to be pressure regulated or not as I hardly ever worked with gas in that format, and when I did, I always dealt with the "end" product. It really doesn't matter though, the end result is the same, the machine is fed a low pressure gas supply vs a typical gas cylinder that contains high pressure gas.
The "problem" with your flow meter is that it lacks the pressure reducing portion of the system from what I can tell. By "problem" I mean you need some way to regulate the high pressure gas down to a pressure the flow meter can work with. What that intermediate pressure is, I have no clue, but you can probably look it up with the model number off the flow meter.
The flow meters I listed earlier do both. They step down the pressure from the cylinder and allow you to adjust the flow of gas. These will not work in conjunction with what you have currently, but will work in place of it. These are designed to connect direct to the high pressure cylinder and provide gas to the machine at a set flow rate. No other equipment is needed ( except of course the hose)
To make what you have work, you need a regulator, not a flow meter. There is a difference. A regulator like for say O2, puts out a constant pressure. A flow meter puts out a constant volume of gas. I have a few old O2 regs that would probably work with what you have, if you changed over the gas fitting for the cylinder. Problem is I have no idea what the pressure needs to be set at to get the flow meter to put out the correct volume of gas as listed on the sight glass. I'd also have to get one of the flow checkers to be able to verify what the flow was, and adjust the input pressure as required. All this is overly complicating a simple thing. The only reason I'd go this route is if you already have a suitable reg you are not using. ( I've got a couple of "questionable" O2 regs I've picked up as yard sale finds for conversion to high pressure air) Otherwise it's just not practical or cost effective.
If you simply went and got a flow meter and hose assembly like this one, you would have everything you need. ( I can't remember if one of the other links I posted up before had the hose with it or not. Most were strictly the flow meter and you'd have to add the hose to the flow meter.)
http://www.arc-zone.com/index.php?main_page=product_info&cPath=437_1485&products_id=7920
