Calibrating Hydrometer

[wyane]

Last night I dropped my 20yo glass hydrometer Pretty peeved with meself too, particularly after digging out the plastic Coopers one ... with plain 20C tap water in it it reads 0.986, way away from 1.000.

So, is this thing even worth using? Can I just add 0.014 to each reading or is it just gonna be so out of whack as to be useless?

 

[Blitzer]

Last night I dropped my 20yo glass hydrometer Pretty peeved with meself too, particularly after digging out the plastic Coopers one ... with plain 20C tap water in it it reads 0.986, way away from 1.000.

So, is this thing even worth using? Can I just add 0.014 to each reading or is it just gonna be so out of whack as to be useless?

haha mine reads the same, I just do the addition but I have no idea I'm just a newbie.

 

[tallie]

Assuming the paper scale has just slipped and has returned to a fairly static position, you should be fine. If it has cracked and is taking on liquid, your results might be a bit more variable. I'd check it in water regularly for the near future to make sure it remains constant.

Cheers,
tallie

 

[Amber Fluid]

With a Hydrometer that is not calibrated and provided it works, it will still do the same job you need it for. i.e. you will still get the same ABV% result and it will still let you know when your beer has finished fermenting. All it won't do is give a correct Gravity reading and this can be calculated as you say.

 

[bum]

That is the calibration, innit?

 

[wbosher]

I had the same problem with my Coopers one. I contacted Coopers to see if they would replace the faulty one and they advised that while there have been some faulty ones that take on water and sink, most can be calibrated. This is done by snipping of a little bit of the red plastic at the top, making it lighter and then it will rise in the water.

Mine was sitting on about .993 and I took of about 10 -15mm and now it's perfect.

At .986 it will take a little more, but just snip a little at a time and it'll come right.

 

[jaypes]

I'm only a noob but I would buy a new one.

If it aint broke dont fix it, but in this case it is broke

 

[wbosher]

The red bit at the top is there for calibrating, but if it's too far out and taking on water then contact Coopers. They got back to me really quick.

Their reply

It’s not necessarily faulty mate – the red tip on the top is intended as a calibration tool. You snip bits off it to make lighter and therefore sit higher in the sample. Try cutting about half off to start to with.

To be fair, we have had the odd (rare) faulty hydrometer that takes on water and sinks to the bottom of the sample tube, but yours is not one of those by the sound of it.

 

[Amber Fluid]

I'm only a noob but I would buy a new one.

If it aint broke dont fix it, but in this case it is broke so fix it if you can.

 

[wyane]

I immersed it overnight and it's definitely not taking on water. Will trim the tip and see how it goes.
Thanks for the suggestions!

 

[wbosher]

Take off about 5mm at first and then a little bit at a time.