Here is one other thing about measuring heat by boiling water. I recommend you put the entire vessel on a weight scale, if you can. Weigh it before and after the test. That is better than pouring out the remaining water and weighing it. You may fail to account for a lot of water when you pour it out. Water will steam away as you pour it out, and a lot of water will be left inside the vessel.
You may not be able to weigh the whole kit and caboodle. If the vessel is heavy, a weight scale that goes that high will be imprecise. That's not good. You want to weigh to nearest ~10 g I think. Or, if the vessel has many hoses and wires that cannot be easily detached, you cannot weight it. - Jed
