Mass flow controller with Labview

[Bozhidar4o]

Thank you! Tomorrow I will find such supply and test the MFC again. 

Probably the ground I have to use as power common. Right?

[altenbach]

Yes, there is a connector labeled "power common". That's probably it.

If your company or institute has an electronics shop, talk to them .:D 

[Bozhidar4o]

First of all I would like to thank you for the support and advices especially to Altenbach.

I tested only one MFC and it works. Find attached the scheme. I could not find such supply and I used two power supplies (attached amateur workplace). The block diagram is very simple: just send voltage 0-5 and the output shows the flow. The response is fast.

[Blokk]

I am happy to hear it works, so the guessing about the wiring was right 🙂 It was also good to learn about analog control of these MFCs from Altenbach, so far i only used RS232...

By the way, you wanna control 3 MFCs, right? Do you have a second USB-6009? The 6009 module has only 2 analogue outputs so you can control 2 MFCs but not 3...

[Bozhidar4o]

Actually you can control the MFC only with power supply and voltmeter.
I have to find NI device with more than 5-6 analog outputs for the temperature and etc. Any proposals? It must be cheap and available on ebay.

[Blokk]

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@Bozhidar4o wrote:

Actually you can control the MFC only with power supply and voltmeter.
I have to find NI device with more than 5-6 analog outputs for the temperature and etc. Any proposals? It must be cheap and available on ebay.

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You mean, you need several analog outputs for the MFCs (so 3 AO channels, and 3 AI channels for reading back the actual flows), and you want to measure temperature also? What kind of temperature sensor you want to use? Thermocouples, RTDs, thermistors, etc?

edit:

Actually you can control the MFC only with power supply and voltmeter.

Hmm, yes you need power supplies (6 pieces for your 3 MFC if the PSU has only single outputs), and 3 voltmeters to read back the flow at the analog outputs. But what about the 0-5 V DC control signal?

edit2:

If you need several analog outputs/inputs, and also several thermocouples inputs, I would go for a NI cDAQ modular system. However I have no idea if you can get these cheap as second hand, but if you are lucky...? You could also consider non NI measurement/control systems but I am not experianced with these...

[Blokk]

Hmm, yes you need power supplies (6 pieces for your 3 MFC if the PSU has only single outputs),

Hmm, the above statement is not true, since you can connect PSUs electrically parallel to the MFCs, as far as the electrical currents do not go over the limit...

So in principle I think you can supply the 3 MFCs with only using two PSU, I think...Sorry, I again posted before thinking 🙂

[Bozhidar4o]

Today I tested the system with 3V bateries and potentiometer. It works. Than I replaced the bateries with USB-6009.

I need several AO and AI. Find attached the scheme of the catalytic system I am building.

I will use Labview. There are mass flow controllers, temperature controllers, gas analysis (voltage vs time) etc. It will be complicated and the timing and the schedule is crucial. I have gas chromatograph and parts for mass spectrometer. Also several gas sensors. Reactors and 6 way valves are available. I need appropriate NI device and some help with writing the code.

I will appreciate any help or advice. Just skip the negative posts with "no way" , impossible and similar.

[Blokk]

A collegue just built a micro-GC system using Bronkhorst pressure regulators and flow controllers (these were controlled via RS232 ports), he bought the multi-channel Thermal Conductivity Detector (TCD) ready made from a company.

He used Neon and Argon as carrier gas. The goal was here to be able to measure micro-liter amount gas samples, which is not really available in commercial devices (at least for hydrogen isotopologues, hidrogen/deuterium, HD).

Can you count how many analog input/output channels you need in total + the number of thermocouples (K-type TC? or something else?) ?

You only want to measure temperature, or also control/regulate it using a heater? If so, I would buy a cheap PID controller including current relay + heating wires/tapes from ebay...

[Bozhidar4o]

I do not have to use microliters because the gases I use are cheap. I have several PID regulators (OMRON, TC- K type) and Thermal Conductivity Detector but I would like to use one single program which control everything (option remote control). For example 8AO, 15AI. I will add heater and Solid state relay and..... etc.

What device (NI) is appropriate?