ok, now here's a question i can help with (i'm usually asking them here)(posted 8527 days ago)anyway, if you want to do a very simple test for this all that is required is a small scale and graduated cylinder/beaker or something you can measure a known volume in... example using 100ml xtol at specified temperature: first get a tare weight of your cylinder/beaker then fill with the xtol to the 100 ml mark, now take your gross weight, subtract the tare weight... if you get 108.5 grams then you nailed it!
results can vary depending on accuracy of everything you use, use large amounts if more accuracy is wanted as small errors become less significant with larger test amounts
if you want to try other numbers remember specific gravity and density are basically the same but sg is dimensionless and you need to use metric units for this to work, density = mass/volume in units could be grams/ml so you can use what ever you need
as for xtol, i've tried one 1 liter pack for some high speed stuff and it worked very nicely for me, i did everything at 1:1 and will use it some more as i often have to shoot 1600-3200 asa
good luck joe
ps- if you want to check the pH you will need a digital probe (you can sometimes find them for reasonable price in fishing catalogs) as you'll never be able to tell close enough with pH paper