Alternatives To A Sight Glass For Volume Measuring

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Thirsty Boy

ICB - tight shorts and poor attitude. **** yeah!
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I don't really like the idea of sight glasses.Yeah I know that lots of people use them and they are fine etc etc... but to me its just another inaccessible place for grunge to build up.

So I've been tossing round and adopting some alternatives....

Kettle - well, I just went with the tried and true dipstick. A stainless steel 1 meter ruler and an hour calibrating it with water in 1L increments. Solved

HLT - I'm using my kettle at the moment until I revamp my electric HLT. It is going to be an old fermentor... transparent with built in calibration marks. Done

Mash Tun - My mash tun is transparent too. Its a 47L plastic storage box. I have simply marked the side of the tun in 1L increments with permanent marker. Done

The HLT alternative that I nearly went with... a float stick. Get a styrofoam ball and jam a long piece of dowel (or something similar) into it. A bit of hard tubing to use as a guide so it always floats vertically, then you mark it where it exits the guide tube in 1L increments as it floats higher and higher when you fill the tun.

So what else are people using to measure liquid levels? yeah yeah I know - sight glasses - but apart from that?

Eventually my whole brewery will be stainless and I wont get away with the whole being able to see through the vessels thing anymore. Looking for inspiration.

Thirsty
 
I suspend a S/S ruler over the edge of my HLT. It is calibrated so that it starts at 0 at the level where the outlet tap no longer drains, that way I don't worry about deadspace.

I made up a table so that I can convert the scale on the ruler to litres. The whole thing is much less cleaning intensive than a sight glass.
 
I use a sight glass in my HLT Thirsty, can't see any issues there, and graduations marked on the inside of the kettle, totally agree there. I can't see the need for any measuring in the mash tun though mate.

cheers

Browndog
 
:icon_offtopic:

Thirsty how much temperature loss do you suffer with your mash tun? I'm looking for a cheap upgrade until I can afford a more permanent solution and I have hundreds of those plastic bucket things ranging from 1 ltr to 160 ltr.
 
I don't really like the idea of sight glasses.Yeah I know that lots of people use them and they are fine etc etc... but to me its just another inaccessible place for grunge to build up.

So I've been tossing round and adopting some alternatives....

Kettle - well, I just went with the tried and true dipstick. A stainless steel 1 meter ruler and an hour calibrating it with water in 1L increments. Solved

HLT - I'm using my kettle at the moment until I revamp my electric HLT. It is going to be an old fermentor... transparent with built in calibration marks. Done

Mash Tun - My mash tun is transparent too. Its a 47L plastic storage box. I have simply marked the side of the tun in 1L increments with permanent marker. Done

The HLT alternative that I nearly went with... a float stick. Get a styrofoam ball and jam a long piece of dowel (or something similar) into it. A bit of hard tubing to use as a guide so it always floats vertically, then you mark it where it exits the guide tube in 1L increments as it floats higher and higher when you fill the tun.

So what else are people using to measure liquid levels? yeah yeah I know - sight glasses - but apart from that?

Eventually my whole brewery will be stainless and I wont get away with the whole being able to see through the vessels thing anymore. Looking for inspiration.

Thirsty

Just an idea,
a large set of scales to weigh the tanks is another way, maybe a cheap set of bathroom scales? I used load cells in my new brewery which is then input into a pc.
 
I use a sight gauge on my HLT, and a calibrated dipstick in the kettle.
 
The scales idea is a good one - water density is about 1g per mL (kilo per litre), so once you've tared the scales with the HLT, you could monitor the drop in weight. You'd want some pretty accurate scales though - and leaning on the HLT would become a no-go!

The sight gauge was going to be the next addition in my brewery... I'm still gravity fed, so I'm at full stretch looking into the HLT with a calibrated dipstick. I use the same dipstick (different scale) for the kettle.

I've looked at depth gauges for rain tanks etc, but they don't seem to be accurate enough (they're more of a ball-park guide). The floating dowel has potential though... I'll keep watching!

EDIT: Here's a link to the "Levetator" tank gauge

MORE EDITS: If you want to go technical, there are electronic fluid depth indicators like this too

...if you're really clever, there's always sonar ;)
 
How much should a 1 metre ss ruler cost and where's the best place to get one?

I currently use a graduated piece of aluminium but it's getting a bit bent these days and I'd like to replace it.

I had a look in Bunnings the other day and they seemed pretty pricey - $30 plus.
 
Damn, knew I was forgetting that styrofoam addition. :rolleyes:

If I decide to go beyond sightglass, I'll build a pressure sensor input to my temp controller to measure depth. I'll then be able to give it a lookup table (because my vessels have ridges in the sides, so volume != k*depth) and put the volume readout on an LCD. It'll then also be able to protect my elements, by turning them off before the level gets below them.
 
Hey Thirsty

My HLT is just an old fermenter with markings on the outside but my kettle is a SS keg. With that I've calibrated and marked the inside with one of those white paint pens that mechanics use. Once dry it lasts for years before you need to re-mark & that's with scrubbing with a nylon scourer after each brew. Makes life really simple , no dipstick no floats just fill to the line. Same process can be used for the mash tun.
 
Damn, knew I was forgetting that styrofoam addition. :rolleyes:

If I decide to go beyond sightglass, I'll build a pressure sensor input to my temp controller to measure depth. I'll then be able to give it a lookup table (because my vessels have ridges in the sides, so volume != k*depth) and put the volume readout on an LCD. It'll then also be able to protect my elements, by turning them off before the level gets below them.

Pressure sensors work such as the mpx10 piezo style but have some cons.. If they get liquid or steam in them them they don't' work, if you put them above the liquid on a tube, the air in the tube heats up and changes your pressure resulting in false readings.. There are very expensive industrial style sensors available that are totally submersible and also ones that use a diaphragm. I have played around with these for too long. I have figured that weighing the vessels has less variance and is not susceptible to changes in liquid viscosity or temp..
 
...if you're really clever, there's always sonar ;)
I'm seriously contemplating this for when I build my electric HLT (still a few months off, as I need to get a new Al pot, the element, and the control parts past the MoF). It's not as hard as you might expect if you have a reasonable grasp of electronics.

It's quite easy to get down to a little over 4 mm resolution using off the shelf components. I'll be using a pair of 40kHz transducers from Jaycar, a PIC16F628 or 877 (it's overkill, but I've got 20 of the buggers sitting on my desk), and a fairly straight-forward amplifier.

The basic principle is to fire a series of pulses, and time how many periods later you get the response. Calculate the distance, and halve it.

I reckon 4mm is more than enough resolution for me (it's about half a litre on a d=400mm pot). It is possible to get even better resolution with a bit of signal processing, but I have no idea how much error you'd be introducing (I do intend to find out though :p).

if you put them above the liquid on a tube, the air in the tube heats up and changes your pressure resulting in false readings..

That won't be an issue if the tube is completely open at the water end though, will it? The expansion of the gas in the tube is the result of the pressure equalising. The pressure exerted by 50cm of gas is negligible compared to the pressure exerted by a few centimetres of liquid.

The biggest technical drawback is that the pressure of a few centimetres of liquid is insignificant compared to the fluctuations in the atmospheric pressure exerted on the surface of the liquid. It's easy to fix though. Just put another sensor outside the tube.

I've put a bit of thought into this idea before, and I could never think of a good way of protecting the sensors from moisture though. I'm not good with building housings...
 
I'm seriously contemplating this for when I build my electric HLT (still a few months off, as I need to get a new Al pot, the element, and the control parts past the MoF). It's not as hard as you might expect if you have a reasonable grasp of electronics.

It's quite easy to get down to a little over 4 mm resolution using off the shelf components. I'll be using a pair of 40kHz transducers from Jaycar, a PIC16F628 or 877 (it's overkill, but I've got 20 of the buggers sitting on my desk), and a fairly straight-forward amplifier.

The basic principle is to fire a series of pulses, and time how many periods later you get the response. Calculate the distance, and halve it.

I reckon 4mm is more than enough resolution for me (it's about half a litre on a d=400mm pot). It is possible to get even better resolution with a bit of signal processing, but I have no idea how much error you'd be introducing (I do intend to find out though :p).

:eek:
I'm seriously impressed :beerbang:

I was taking the mick!

If you go ahead with the project, please keep us all informed. A brewery with sonar wins in the bragging rights arena IMO.
 
Thanks guys.. you electronics types freak me out... but sonar would be cool.

The vessels at work use a combination of sonar and motion detectors to work out when levels are changing and what they actually are, I could probably get an instrument tech to whip one up for me for a few slabs... but then I'd have to deal with it and thats too much brain power for me.

Actually, I like the idea of marking the inside of the kettle the best. Didn't know that you could get stuff robust enough to deal with all the boiling and scrubbing. Still, it would suffer from the same problem as the dipstick. I have to stand on a step stool and shine a torch in the kettle to take a reading. Not too bad, but less than ideal.

RobW - Stainless ruler - about $5 from an Asian $2 shop on Victoria st Richmond

Browndog - Need measurements on Mash tun because I filter cold strike water directly into the Mash Tun and need to know when to stop. Heated up via HERMS.

Zoddy - No temperature loss - I run a HERMS so I don't worry about insulation. With a bit of camping mat though, I cant see why it wouldn't hold heat at least as well as a stainless or Aluminium pot and plenty of people use those.

Cheers

Thirsty
 
Sonar sensors are a bit difficult to waterproof, but with processors as fast as they are these days, it might *almost* be possible to do it with infrared.

Much to Thirsty Boy's frustration, all my volumes before fermenter are measured in centimeters...
 
Sonar sensors are a bit difficult to waterproof, but with processors as fast as they are these days, it might *almost* be possible to do it with infrared.

Much to Thirsty Boy's frustration, all my volumes before fermenter are measured in centimeters...
You can get water-resistant tranducers off the shelf. They're encased in aluminium. Infrared would be nice. Instead of measuring your volumes in centimetres, you could measure them in microns! :)

Infrared is a bit of a way off for the home tinkerer. It's obviously able to do sub-micron resolution in theory, but you'd need something really fast counting periods to see the full resolution:
For light, f=c/λ. Lets use λ = 1μm (they're normally a bit lower than that off the shelf), c=300Mm/s, so f = 3e14. That means you'd need to be able to count at 300GHz to see micron accuracy.

To get the same resolution as an ultrasonic sensor, you can pretend that λ=8.25mm, which gives you an apparent frequency of 3.6GHz. That's not really on option.

If parts available at Jaycar, you could probably get a resolution of 15 metres using infrared, by my calculations :).
 
That won't be an issue if the tube is completely open at the water end though, will it? The expansion of the gas in the tube is the result of the pressure equalising. The pressure exerted by 50cm of gas is negligible compared to the pressure exerted by a few centimetres of liquid.

It gave me a hell of a lot of grief, worked fine with cold water, as soon as you heated it up the levels started drifting.


The biggest technical drawback is that the pressure of a few centimetres of liquid is insignificant compared to the fluctuations in the atmospheric pressure exerted on the surface of the liquid. It's easy to fix though. Just put another sensor outside the tube.

Thats not a problem as the sensors are differential, one side is your process pressure the other is atmosphere.

I've put a bit of thought into this idea before, and I could never think of a good way of protecting the sensors from moisture though. I'm not good with building housings...

The good sensors are oil filled and use a diaphragm.
 

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