7 in 1 water tester

[Hacksawbob]

Has anyone tried one of these?
From our Sino ballon masters on Aliexpress so don't click the link if you don't want president Xi knowing your every move so I'll put the specs at the end.

7 in 1 tester

PH testing nice, but the thing I spotted was specific gravity test. Now it is for saline gravity, but gravity is gravity right and auto temp correcting too?

Water Quality Tester Specifications:​

PH Range: 0.00-14.00

Resolution: 0.01ph

Accuracy: ±0.5ph

Temperature Range: 0.1℃-60℃ 31.2℉-140.0℉​

Resolution: 0.1℃/0.1℉​

Accuracy: ±0.5℃​

EC Range: 0-9999us/cm , 10.01- 19.99mS/cm , 20.1-400.0mS/cm​

Resolution: 1uS/cm 0.1mS/CM​

Accuracy: ±2% F.S.​

TDS Range: 0-9999ppm，10.1- 200.0ppt​

Resolution: 1ppm​

Accuracy: ±2% F.S.


ORP Range:±999mv

Resolution: 1mv​

Accuracy:±2mv​

Salinity Range: 0-10000ppm , 10.1-200.0ppt , 0.01%-25.00%​

Resolution: 1ppm 0.1ppt 0.01%​

Accuracy: ±2%FS. 0.01-5.00% (±0.1%) 5.1-25.0% (±1%)​

S.G Range:1.000 -1.222​

 

[RichardM]

If the SG is measured by refraction of light passing through the liquid, as it is for a standard refractometer, the I don't think it will work because wort will have a different refractive index to a saline solution for a given SG.

 

[Sadfield]

Accuracy: ±0.5ph

Useless. If you are aiming for a mash pH of 5.4 and it displays 5.4 it could actually be 4.9 or 5.9 and outside the desired range.

 

[Agentgonzo]

If the SG is measured by refraction of light passing through the liquid, as it is for a standard refractometer, the I don't think it will work because wort will have a different refractive index to a saline solution for a given SG.

This happens for normal refractometers that are calibrated for fructose rather than maltose and can be corrected by just multiplying by a "wort correction factor". I wonder whether the same could be done to convert the salinity into SG?

That's assuming that it measures the salinity via refraction. If it measures it via conductivity () then it probably wouldn't work for wort

 

[Hacksawbob]

Useless. If you are aiming for a mash pH of 5.4 and it displays 5.4 it could actually be 4.9 or 5.9 and outside the desired range.

Yes I take your point, not great accuracy.

 

[peebee]

I think some of the answers above are over-complicating how it most likely measures "SG". The tester looks much like many other testers of that ilk and I don't think it'll have crammed in an extra "optical" analysis device. If it somehow did, the market would be awash with such devices measuring Brix, etc.

Note there is no "accuracy" figure for SG.

But it, and the others of that type, can measure TDS* (total dissolved solids), and if restricting the function to a "saline" could assume the salts being tested (like it'll be various chlorides). If you have a known concentration of an assumed saline solution, it could return an approximate SG for the solution.

It's a pH tester, ignore the SG boll****. "SG" really would be stretching the imagination a little too far? And it won't work for sugars!



*It measures conductivity of a liquid and there's a rough correlation between conductivity and TDS.

 

[Hacksawbob]

I went to beer X and was chatting to the guy from Anton Parr who had some portable gravity testers (not much change from 2.5K if you were going to ask) I asked how it worked, there is a vibrating tube which measures the change in oscillation due to different density of liquid. Clever stuff. No if I could only hack a guitar tuner to do the same!

 

[peebee]

"Oscillating U-tubes"; just the job! Soon we'll all have them and wonder what we ever saw in Archimedes' "Eureka" inspired device (though it wasn't until 18th century before anyone clicked you could predict the strength of your beer/wine with the things). Meanwhile, if you figure out how to adapt your guitar tuner, let me know!

Whatever I saw in those "Eureka" inspired devices, I wiped from me 'ead when I ditched my last shattering glass demonstrator (otherwise known as a "hydrometer"). Cheap accurate weighing scales make the hydrometer alternative far more useful (and far more accurate). I never waste an opportunity to bore everyone mentioning them: "Pyknometer bottles" (bottles with a hole in the stopper). They can measure "relative density" (aka "specific gravity") because it was designed for these types of "instrument", not flippin' "hydrometers". "SG" provides a sort of temperature compensation. That's not what "hydrometers" use it for! Hydrometers have more in common with Plimsoll-line markings on ships than brewing beer.

Rant. Rant. Rant. I hate hydrometers ... you can tell? Now where do I buy a guitar tuner? ...

 

[peebee]

Remarkable what a good rant can do for the thinking ...

Homebrewers are often grumbling that their hydrometer is probably inaccurate, that it doesn't read 1.000 in water at 20°C, etc., etc. Well, here's a solution:

Smash the flippin' thing on the floor, jump up-and-down on it (at a rough frequency) and guess. Sort of oscillating tester and possibly more accurate?

Na, na, na, na ....

Measure your beer with the "defective" hydrometer. With the same hydrometer measure plain water that has been kept near the beer for an hour or so. So that it's the same temperature. Divide the measurement of the beer by the measurement of the water. Hey presto ... "Specific Gravity"! Oh, and you can ignore temperature, it's been compensated for automatically. The faulty measurements mean nothing, it could be "quazzy beans" we just want a ratio which is what SG is.

Wow ... don't know why I've never thought of it before! Or why I've never heard anyone else suggesting it? Perhaps I finally fallen over the edge and flipped completely? If I haven't flipped, someone, somewhere, has already got it published ... show me, show me, pleaaaassse!

Everyone reading this is now trying to prove what a total Idjet PeeBee is



e.g. "SG" of beer measured with defective hydrometer: 1.086
... "SG" of water measured with same defective hydrometer: 1.005

"Real" SG of beer: 1.086/1.005 = 1.0806 (relative to water at the same "undetermined" temperature).

Let's try that again with the defect going t'other way ...

"SG" of beer measured with defective hydrometer: 1.074
... "SG" of water measured with same defective hydrometer: 0.995

"Real" SG of beer: 1.074/0.995 = 1.0794 (relative to water at the same "undetermined" temperature).

(They weren't reversed engineered to finish identical - it's just an illustration). The "defective" numbers are irrelevant, as long as they both come from the same linear scale on the same measuring device.

This is all going to fall about me ears! But for now, I can bask in the glow of my brilliance! Too late, I've just illustrated to the world what a dip-stick I am. Or perhaps I'm not?



The easier way is if reading water at +0.005, simply delete 0.005 from the beer's measurement. But the "ratio" means does allow for the scale to have stretched (or shrunk). Or changes in temperature!

 

[Hacksawbob]

well if people are going to get their pants in a twist over .0005 of a point then I direct them to the Anton Parr device above. We all have an in built tilt ABV tester. standing upright is 0% pure water, lying down is about 2L of 10% divide by the number of degrees you are off vertical and you have your ABV, temperature corrected as well!

 

[Druncan]

No way @peebee I love my saccharometers nestled in their cosy tool box and only brought out for genuflection with OG and FG. They work and Brewlab say my calculations work.

 

[MashBag]

I am with you Peebee.
I don't think good beer needs gadgets, it needs brains and we all have one.

 

[peebee]

I thought I'd accumulate loads of replies from people wanting to prove what an idjet PeeBee is. But not a bit of it. Perhaps I was writing down the obvious and only demonstrating how slow I can be at times? I no longer doubt what I wrote, it's all fairly straight-forward. But I will criticise something @MashBag said:

... it needs brains and we all have one

Me? Got "one" brain? I've seen the scans after me accident, and I've most certainly got slightly less than "one"!

The reason, I think, most people have trouble with all this "SG" gooble-de-**** is that we (not Americans and some others about the world who hang on to some extraordinarily arcane measuring units) measure density in grams per millilitre which looks very like "SG". But they are not the same.

Everyone knows water has an SG of 1.000. But some may point out "but only at 4°C, not at 20°C, when it's 0.9982 g/ml". Except: Measure water, the liquid we use as a "reference", at 20°C and we get 0.9982 g/ml, and 0.9982/0.9982 is ... "1.000"! That's why it's called "specific gravity" ... yeahhhh

Except I haven't a clue why they called it "specific gravity"! The other name makes more sense ... "Relative Density". "Relative to water" that is. I'm sure @Hacksawbobs "Anton Parr" device will display as "SG", "Relative Density", "gms per ml", etc., etc.


Think I'm clever? Have you any idea how long it's taken me to drum all this in me 'ead? Now I can even quote the density of water at 20°C without looking it up. That's got to help me get through life ... ?


Footnote:
Just remember: Armed with a dodgy as dodgy can be hydrometer (which you don't drop and smash), some clean water, a hydrometer jar and a calculator ('cos we're all useless at doing maths in our 'eads these days) you can take perfectly accurate "SG" readings, and not even be aware of the temperature. Note! A hydrometer, not my usual pyknometer. Ouch ... was I aiming for my foot?

[EDIT: "Perfectly"? I'm exaggerating again ... must stop it.]

 

[Agentgonzo]

At the end of the day, the hydrometer/pyknometer/refractometer/wobbleometer tells you your ABV. It's handy to know whether "you can have 3 pints of this beer" or "half a pint will put you on the floor", but after that the accuracy of the ABV for homebrew isn't really that important. I went for many years brewing ~5% ales and stopped even measuring it at all and just telling friends it "was about 4-5%" (which it was from experience of the grain bill).

 

[Sadfield]

Reliable gravity readings at various stages can tell you all sorts of things. Issues can be spotted and remedied.

 

[peebee]

...
Footnote:
Just remember: Armed with a dodgy as dodgy can be hydrometer (which you don't drop and smash), some clean water, a hydrometer jar and a calculator ('cos we're all useless at doing maths in our 'eads these days) you can take perfectly accurate "SG" readings, and not even be aware of the temperature.

Don't go mad with this! It's not mathematically perfect, just gets you out of a scrape when you're mistrusting your hydrometer.

I thought I'd see how far I could get away with it and chucking your 20°C calibrated hydrometer in 50°C wort will misread (once corrected!) by about one gravity point under (standard 3DP resolution). Not actually that bad, but more likely the hydrometer will break with the thermal shock!

If the hydrometer is misreading in water by more than five-or-so gravity points, the results are likely to be getting noticeably off track.


Pyknometers are still miles better!

 

[Agentgonzo]

Don't go mad with this! It's not mathematically perfect, just gets you out of a scrape when you're mistrusting your hydrometer.

I thought I'd see how far I could get away with it and chucking your 20°C calibrated hydrometer in 50°C wort will misread (once corrected!) by about one gravity point under (standard 3DP resolution). Not actually that bad, but more likely the hydrometer will break with the thermal shock!

If the hydrometer is misreading in water by more than five-or-so gravity points, the results are likely to be getting noticeably off track.


Pyknometers are still miles better!

If you chuck you pyknometer into 50°C wort it probably won't fare very well either

 

[Cwrw666]

I think Peebee is a bit biased against hydrometers. As to thermal shock - I sanitise mine by running boiling water down it. Never been a problem and don't ever remember breaking one. This one's at least 30 years old

 

[peebee]

If you chuck you pyknometer into 50°C wort it probably won't fare very well either

Nope, not these cheapo Chinese 20ml bottles I've got.

However, the 50ml bottle is borosilicate glass. It should be fine. But replacing it will cost a fortune, so no way am I trying it!

Peebee is a bit biased against hydrometers

No I'm not! How can you say such a thing. I've got nothing against those cr**o, ludicrously fragile, bits of Xmas Tree tat ...

 

[Agentgonzo]

Nope, not these cheapo Chinese 20ml bottles I've got.

However, the 50ml bottle is borosilicate glass. It should be fine. But replacing it will cost a fortune, so no way am I trying it!

I was meaning chucking the entire pyknometer into the wort, not the bottles...