Calibrating a measuring stick?

DC · Post by DC » Mon Jul 13, 2015 2:40 pm

Hey all, I am looking to calibrate my Burco Boiler and I am thinking of using a stainless steel rule as a measuring stick. I know some people have used wooden spoons or sticks and marked the graduations on the spoon / stick as they go. This might be a daft question but if I am using a stainless steel rule as a measuring stick do I need to add something to the water so the level shows up on the rule as I add water to my boiler? I know if you use wood you can just see where the water has gone up to and mark the stick then dry it and carry on marking off as you fill the boiler. But with a stainless steel rule it’s going to be hard to see where the water level is and be able to mark the rule. Unless I get a length of wood the same length as the rule and then mark the wood and then transfer the graduations to the rule when I’ve finished calibrating the boiler?
I want to stamp the litres on the rule with a set of punches

Told you it was a Daft question

Cheers DC

Goulders · Post by **Goulders** » Mon Jul 13, 2015 3:05 pm

It's quite obvious because you will see a wet line on the ruler where the water level is. Try it and you'll see what I mean.
I have made a spreadsheet (or you can calculate manually what the volume is and then do the markings). Below assumes a flat bottom.

V= Pi x r^2 x h

So calculate height(h) if r=19.2cm, Pi=3.146, and V= 1 litre (1000ml)

1000 = 3.146 x 19.2 x 19.2 x h

h = 1000 / (3.146 x 19.2 x 19.2) = 0.86 cm

For 2 l, use V = 2000

h = 2000 / (3.146 x 19.2 x 19.2) = 1.72 cm

Jocky · Post by **Jocky** » Mon Jul 13, 2015 3:10 pm

I just bought a 60cm long steel ruler for about £3 off ebay, and then wrote a table of depth vs volume, which I have pinned up.

http://www.amazon.co.uk/Silverline-MT68 ... teel+ruler

Dip ruler in - 470mm
Look up on chart - 470mm = 19 litres.

vacant · Post by **vacant** » Mon Jul 13, 2015 4:57 pm

Does the temperature of the water/liquor/wort affect the linear measurement significantly?

Post by **f00b4r** » Mon Jul 13, 2015 5:49 pm

You can measure the distance from the top rather than from the bottom to calculate your current volume (effectively measuring head space from known total volume off your urn). Biabacus has a section for this.

Post by **f00b4r** » Mon Jul 13, 2015 5:51 pm

vacant wrote:Does the temperature of the water/liquor/wort affect the linear measurement significantly?

It does to an extent, you can check this on Biabacus as well, 21L of cold wort expands to about 22L when heated near boiling.

alexlark · Post by **alexlark** » Mon Jul 13, 2015 8:05 pm

When you put the steel rule in the water just read the measurement the water level goes up to, pull it out and mark it.

DC · Post by DC » Tue Jul 14, 2015 12:05 pm

Hi guys, I tried just dipping the stainless rule into the boiler and pulling it out and marking it ! But by the time I had removed the rule from the boiler I could no longer see a mark to show where the water had been up too

So that's that Idea scuppered

Might have to find a thin piece of wood same size and thickness as rule and use that so the water doesn't displace much

cheers DC

Post by **f00b4r** » Tue Jul 14, 2015 12:43 pm

Can you not just put the ruler to touching the water level and read the measurement on the ruler at the top lip of the boiler?

BenB · Post by **BenB** » Tue Jul 14, 2015 3:43 pm

http://www.ebay.co.uk/itm/Bahco-CS400-C ... 1140834403

is what I use. Rest the handle on top of the side of the boiler and drop down the ruler bit to the top of the water / wort and read off the scale at the handle. Job done. Nice and accurate and repeatible.... And it's stainless....

barry44 · Post by **barry44** » Tue Jul 14, 2015 7:59 pm

I used a marker on a plastic ruler.

Drew a new line each litre.

I've ordered a stainless one to replace due to bending issues and will do the same thing although I like the idea of using wood to assist.

sbond10 · Post by **sbond10** » Tue Jul 14, 2015 11:13 pm

Bulldog clip steel ruler slide down to water level lift up mark and repeat

Steve1262 · Post by **Steve1262** » Sat Jul 18, 2015 8:46 pm

You could always cut an upper and lower hole in your burco and fit a sight glass kit and mark the tube with graduations.

DC · Post by DC » Tue Jul 21, 2015 7:14 am

Hi Guys, Just a quick update to say my steel rule is now calibrated

in the end I stuck post it notes across half of the rule so I could see the water marks which then allowed me to mark the graduations on the rule

Cheers DC

Fil · Post by **Fil** » Sat Jul 25, 2015 11:35 pm

ive been using a 500mm SS ruler dipstick in my 100l stockpot 1mm = 2l

i wouldnt leave the ruler dipstick in the hot/boiling liquor too long tho as i dont trust the ink in the gradient markings

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