Machine milled stuff..
Looks good, do you happen to know what year it's made?
I know right! I wish I had a lathe, or even a mill. lol.
I don't know exactly, but since it has the card connector, its clearly a pretty old model.
Im slightly intimidated by all the pins on this thing, lol. Im worried I'll fry something if I hook it up incorrectly. I do have a female card connector to hook up to it though. Im having a hard time finding any documentation for this exact model (or at least documentation that makes it clear what to do if one wants to use this without the original software - which comes on a floppy disk, lol)
I bet the guys at EE can answer. You have an account?
Oh dear, 3.5, 5.25, or even 8" ??? 
For the 3.5 floppies, there re USB readers. I have one from HP.
Lets hope the floppy is readable, and the files are too. Sometimes it's a challenge to read those old file formats.
Lets hope they are source files and not compiled code.
Oh no.. Sorry, I didn't mean that I have the floppy disk, I meant that it originally came with a floppy disk, which I don't have. Thus the "Without the original software".
Sorry for the confusion.
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I'm always curious around this kind of equipment, and googled around for the interface. Null, nada, void. Some hints though from the pinout plate: B,C are signal ground, and pin 3 0-5 VDC. That's probably your sensor output.
This is interesting, there are meters and there are controllers. Both collect data, but the controller can also adjust the flow.
Ahum There should be a power input as well, and I have no idea. Perhaps the seller would know.
It looks like Brooks Instruments bought the group that owned UNIT Instruments back in 2009. If you search your model number you might be able to download a manual. Usually they only have the current products listed but you could try. Sometimes a phone call will get good results.
If you could post pictures of all labels on the device that would be helpful. Sometimes just putting the model number into google gets good results.
Yeah, I also came up with the same results, lol. But there's several videos of people using them with arduinos (including Ben's - I may hit him up and ask, he's usually very helpful if he has time to reply).
Yes, I only wanted to get a meter since I was planning on using one of those needle valves that are controlled with a stepper motor in AC units and refrigerators. But the mass flow controllers were actually about the same price as the sensors. So why not, right?
I did ask them, and they weren't very helpful. I think they just buy and resell them, but don't know much about them other than what you can read on the labels or what may come with them (documents, etc)
The power inputs are the points labeled “+15VDC” , ”-15VDC”, and “POWER COMMON”. Power supplies of that sort used to be fairly common. I am sure they are still available.
My interpretation (best guess) of the other terminals is:
A: SETPT (0 - 5V) - This is the input to the controller for the set point, the desired flow rate.
D: VALVE TEST PT. - This is most likely the signal indicating the controller output to the control valve, most likely a 0 - 5V signal also.
I: AUTO ZERO ALARM- An output from the controller. Probably indicating that the flow sensor does not zero correctly could also be a valve zero fault which indicates that the valve is not shutting completely.
J: VALVE OFF - Most likely an input to allow external logic to shut the valve off. Alternatively it could be an output to indicate that the valve is closed.
3: OUTPUT 0 -5VDC - The actual flow rate. Possibly the output of the controller to the valve not likely because of “D”, above.
I notice that there are several potentiometers on the circuit board. Probably for such functions as setting the controller parameters (P, I and possibly D), and setting the desired flow range of the unit.
As you can see, there is a lot of guessing here. A manual would be nice.
So now that I have taken the time to supply this information, could you please take the time to post pictures of all the labels on the unit. If the potentiometers have labels post a picture of those too.
You have quite some insight, I guess there are 'some' experience here.
Would you say + and - 15 V are needed for the sensor output?
Yes, connect the power supply common to the power common terminal. Bipolar power supplies are very common in analog circuitry, especially those using op-amps. Most of the amps cannot bring their outputs all the way to the negative supply so ii is common practice to use the bipolar supplies and the common is used as a reference for all signals.
Have you tried contacting Brooks?
Hi! I trying to wire this UNIT MFC with Arduino UNO (same model), and I was wondering if you could make it.
Could you tell me what terminals from the MFC did you connect?
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