Calibrating Sight Guage

[bignath]

Gday all and sundry,

I have just built and installed a sightguage in my HLT.

Have a few questions about calibrating it.

1. Those that have done this, did you use water by weight or by volume? I am thinking 1000g = 1lt doesnt it?

If gram for ml is the same thing, i want to go by weight as my scales would be more accurate than the considerably thick lines on my measuring jug. Any problems doing this?

2. Should i use cold tap water or should i use hot water? (not sure at what temp expansion becomes an issue)

Cheers,

BN

 

[clay]

pretty sure 1kg of water is equal to 1L @ 20degrees C

 

[Pennywise]

1L is 1000g

 

[JDW81]

1L is 1000g

I calibrated mine with a 1L pyrex jug and a thin black marker, I reckon its accurate within 200 mls, which is close enough for me.

My 2c

JD

 

[bignath]

Cool, so does it matter about temp?

I source my strike and sparge water from my hot water tap which comes out at around 67/68 degrees?

As my starting volume of water is already preheated, should i make adjustments for expansion?

 

[loikar]

Cool, so does it matter about temp?

I source my strike and sparge water from my hot water tap which comes out at around 67/68 degrees?

As my starting volume of water is already preheated, should i make adjustments for expansion?

Nath,
You're not mixing chemicals here, it's a home brew kettle.
if you're 50ml\100ml\200ml out it's not going to matter much.
Hot or cold, it's irrelevant in this situation.

get a few 1L measuring jugs\containers.

fill one to the 1L mark, and pour it into the next one, does it measure 1L? the pour it into the next one.
essentially find the container that is the most accurate to 1L.

fill your kettle with water, hot or cold, 1L at a time and mark on paper each time you pour one in.
as soon as it hits your sight glass, mark it at that point.
add a litre, mark it.
add a litre, mark it.

when you run out of sight glass, you're done.
Might take a while, but you'll only need to do it once.

found this:
pour a beer before you watch it


BF

 

[bignath]

Just found this on the web.

http://www.engineeringtoolbox.com/water-th...ties-d_162.html

Based on the figures quoted, water at 65-70 degrees has a volume mass of 1.02. Would that be in relation to Water at 20degrees?
If im correct, if for example my strike water was 25lt, wouldnt that really be 25.5lt? Which would mean a differential of 500ml?

Also according to the same chart, at 100deg its 1.04. Is that where the 4% evaporation loss comes from as found in most brewing software?

@beerfingers, yeah i know im getting retentive about it, just wondering what most brewers do, and if theyve thought about it all. Cheers mate.

 

[Cocko]

Big,

No answers, sorry... and a little OT, sorry.

But out of interest, if you are being this anal, can I ask how you are going to be marking it out? As, in direct on the tube or a back plate etc...

I am about to do my new HLT and cant work out the best solution.

 

[bignath]

Gonna do the backplate thing so if my tube gets damaged i dont have to recalibrate.

Im going to get some aluminium bar and drill holes at each end slightly bigger than the tube diameter. Im then gonna bend it into a c channel shape the length of the tube so it can be rotated around the tube and viewable from different angles. Mounting it around the tube also eliminates any problems with it shifting or swaying.

Might take photos when done if youre interested???

 

[Cocko]

Might take photos when done if youre interested???

Sounds awesome, would appreciate some pics when done, cheers mate!


Might do the same..... but stainless B)





edit: Sphelink

 

[JDW81]

Just found this on the web.

http://www.engineeringtoolbox.com/water-th...ties-d_162.html

Based on the figures quoted, water at 65-70 degrees has a volume mass of 1.02. Would that be in relation to Water at 20degrees?
If im correct, if for example my strike water was 25lt, wouldnt that really be 25.5lt? Which would mean a differential of 500ml?

Also according to the same chart, at 100deg its 1.04. Is that where the 4% evaporation loss comes from as found in most brewing software?

@beerfingers, yeah i know im getting retentive about it, just wondering what most brewers do, and if theyve thought about it all. Cheers mate.

I don't bother about temp differences myself, i just fill up my hlt with tap water, heat to desired temp and drain into mash tun. I usually always hit my pre boil volume and my mash efficiency is almost always over 80%.

FWIW I measure my pre boil volume with a dip stick made from a broomstick handle with 1L graduations measured with the previously mentioned pyrex jug. It isn't exact to the mL but works for me.

 

[raven19]

My sight guage with pics here:
HLT Linky

Near boiling water will swell 4% in volume compared to room temp water (approx) so it will have an effect but in the end, once you have your system down pact you will just end up allowing an extra 1L here or there for your typical batch.

 

[DKS]

Gonna do the backplate thing so if my tube gets damaged i dont have to recalibrate.

Im going to get some aluminium bar and drill holes at each end slightly bigger than the tube diameter. Im then gonna bend it into a c channel shape the length of the tube so it can be rotated around the tube and viewable from different angles. Mounting it around the tube also eliminates any problems with it shifting or swaying.

Might take photos when done if youre interested???

Ive made a prototype similar using the ss spear/stem from a 50lt keg. Not installed yet. A bit fiddly but should work well.
Keen to see those pics BN.
Daz

 

[manticle]

Nath,

Why not just mark it at the approximate temperature of your strike water since that's what you'll be using?

Myself I'd just do what beerfingers suggested but I understand the desirte to know stuff that is possibly irrelevant considering the enzymes thread I started yesterday.

 

[Yob]

1 lt increments? :blink:

I find that 5 lt increments are fine, bit of the thumb in the air is OK for me

 

[MaltyHops]

...
Why not just mark it at the approximate temperature of your strike water
since that's what you'll be using?

Well, there're two sides to every story Use left side to callibrate for normal
room temp (say 20C), then callibrate right side for typical strike water temp.
Best of both worlds?

PS. Are you done adding elements, ball valves, etc to HLT? Best to callibrate
after everything is added.

 

[JDW81]

My sight guage with pics here:
HLT Linky

Near boiling water will swell 4% in volume compared to room temp water (approx) so it will have an effect but in the end, once you have your system down pact you will just end up allowing an extra 1L here or there for your typical batch.

I think this is what it comes down to really, you learn the little intricacies of your own system. After a few brews you'll know what to adjust and it won't matter your sight gauge isn't 100% accurate.

I reckon the most important thing to do is make notes with every brew so you can look back and adjust as needed. Maybe thats just me being a bit anal though.

 

[chalky]

You are more likely to introduce more parallax error when reading the sight gauge than the thermal expansion difference of water at room temperature when you marked the sight gauge compared to strike temperature.

Having a non calibrated thermometer will have a far greater difference on the resultant beer than being plus or minus 100ml in your batch of beer.

Just calibrate it with a 1L jug and then reuse the water for something else, maybe even turn it into beer

Just found this on the web.

http://www.engineeringtoolbox.com/water-th...ties-d_162.html

Based on the figures quoted, water at 65-70 degrees has a volume mass of 1.02. Would that be in relation to Water at 20degrees?
If im correct, if for example my strike water was 25lt, wouldnt that really be 25.5lt? Which would mean a differential of 500ml?

Also according to the same chart, at 100deg its 1.04. Is that where the 4% evaporation loss comes from as found in most brewing software?

@beerfingers, yeah i know im getting retentive about it, just wondering what most brewers do, and if theyve thought about it all. Cheers mate.

 

[Bizier]

I totally sympathise with the desire to have a calibrated sight guage. You don't need it, but it would be nice.

I tried with my kettle using single litres from a jug, 5L increments from a bucket and by volume of a cylinder measurement, and all are wildly different. I know that the volume of a cylinder is wrong because of the curved bottom edge and because it is spun so the inner diameter probably changes, but I still believe it to be the most accurate if I add a little (say 1L per 50L) on top to compensate.

 

[bignath]

Here are some piccies of the completed sightguage.

Ended up just calibrating with 2lt increments. Decided to not worry so much about the whole calibrating at strike temp thought process i had going on when i started this thread.

The marking backplate can be moved around the sightguage so it can be read easily from lots of different angles.

Works well so far.

Cheers for everyones input on this.

Brewday tomorrow, so we'll see how it is to work in real life with...