# Cylindrical Tank Capacity

Is there any way to have the capacity of the tank grow as the percentages of gas and the totalizer go up? Right now, the tank capacity is just set to 500,000, but as time goes on the gas percentage and totalizer are going to surpass that amount.

You could bind it to something so that itâ€™s evaluated dynamically, butâ€¦ Itâ€™s a capacity, itâ€™s not supposed to grow. What are you trying to do exactly ?

The capacity of a tank is fixed. If it isnâ€™t then you are describing a balloon.

And mechanical â€śballoonsâ€ť have existed since 1789. See Gas Holder also known as a Gasometer.

But I am not sure what the OPs use case is here.

Thanks, Peter. I had considered the gasometer while replying but reckoned that the graphic â€ścapacityâ€ť would show the upper limit and the â€śvalueâ€ť the actual position.

The tank is representing a gas totalizer and gas percentage amount between specific dates. The point of the tank is to show the percentage of the two gas. For example, if I wanted to see the amount of gas percentage was used between 2020-2021, but another time, I might want to see the amount that was used on the weekend. The capacities would be different in those to instances.
Not sure if that explains the purpose well enough.

Set your capacity to 100 and convert your content to percent to feed the display.

If the goal is to show percentages, then I think the value should be made into a percentage, not an absolute value. Then set the capacity to 100. Thereâ€™s no need for the container to grow here.

The goal is to just represent the percentagesâ€¦ I guess it would be showing the totalizer of the two gasses. I have a screenshot to show how it is represented.

Well Iâ€™ve never used tanks before, butâ€¦ how the hell do you get two different things in the same tank ?

If youâ€™re trying to show two different volumes in one space, look at this Exchange resource: Ignition Exchange | Inductive Automation

@Nicole_Weiss Are you saying for your illustrated tank, that you want the â€śtankâ€ť to show 17% of CO2 and 83% of Ar? If so, canâ€™t you just set the â€śtankâ€ť volume to 100 and pre-scale the inputs by dividing by the Mass totalizer amount (and of course multiplying by 100 to get percent)

I used two separate tanks then just overlapped them. One tank is showing the CO2 % value and then another is showing the Argon %.

Your labels on the left have â€ś%â€ť, but the units on the right are cubic feet. CF != %. Convert CF to % for display.

I guess you could use just one tank and consider the liquid as one gas and the empty part as the other gas ?
In which case you can do something like that:

Or just make your own component with 2 labels with different colors, and adjust their size depending on gas volumes

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I just want the tank capacity to get bigger while the mass totalizer goes up as time goes. The co2 and argon % labels is showing that calculation.

What is stopping you from adding a binding to the capacity to change it based on your need?

I tried this out but I keep getting an error saying my co2 value doesnâ€™t exist. Iâ€™m still new to Ignition so I know I definitely didnt do something right.

Double check the spelling of everything and the paths of your properties.

I did try that, but Iâ€™m not sure if I need a script or expression to make it bigger or smaller depending on the dates selected.