Bomb calorimetry with Mahler's bomb

[capocchione]

Hello,

I need to create a VI in order to measure HHV (high heating value) of a substance.

I have a bomb calorimeter (Mahler's bomb, as in pictures attached) but it is not automatic. I have a RTD Pt100 temperature sensor with a 4-wire configuration wired to a NI CDAQ USB.

My goal is to convert the manual measurement bomb calorimeter I have to a full (or semi-) automatic bomb calorimeter.

Could you please help me?

Thank you so much.

[johnsold]

Are you trying to hire some one to automate this for you? If so, look at the LabVIEW Job Openings Board.

If you want help in learning how to develop your own program, then you need to be much more specific about the kind of help you need. Do you know anything about LabVIEW? Do you have a good specification of exactly what an automatic calorimeter must do? 

Lynn

[capocchione]

Of course I want help in learnig how to develop my own program, I don't want this out of the box.

I'm a LabVIEW newbie, I made a really simple VI to measure temperature of calorimeter jacket, then I use this simple data to do calculation and obtain the High Heating Value of substance.

The theory of HHV measurement, according to ASTM D240-2007 standard (Heat of Combustion of Liquid Hydrocarbon Fuels by Bomb Calorimeter), explains that, firing the sample, the adiabatic jacket water temperature should rise from t1 to t2.

 Recording these two temperatures, and knowing all the other data, the Gross Heat of combustion (HHV) can be evaluated as:

As I said, I record temperature and I wrote down t1 and t2, then I do all the calculations to evaluate HHV.

I just want help to learn how to create a VI to "automate" all these calculations.

Sorry for bad english, thank you so much.

[johnsold]

OK.

t1 appears to occur at an inflection point on the time-temperature curve. Finding that point automatically in straightforward, in prinicple, although in practice it may be more difficult depending on how closely the measured data follows the predicted curve and how much noise is present.

I presume that t2 is the boundary between regions 2 and 3 on the diagram. It is not labelled. How is that point defined? Is it some fraction of the "final" value of the temperature, some predefined temperature, or some other method?

Does your VI acquire the temperature and dispaly a curve similar to the one you have shown? Once you get that far, then you can work on the calculations.

Lynn