Refractometer - wrong type

[trustyrusty]

Hi There, I bought a Refractometer - the one you look through to read through read percentage, however bought for a car . "Automotive Antifreeze Refractometer Car Urea Fluid Tester Battery Freezing ATC Detector Handheld Electrolyte Hydrometer" did not realise..
but to me they all look the same - extremely simple apparatus, I was wondering if I could change the sticker inside to match for alcohol or at least look at a diagram to get an idea, should be the same?

thanks

 

[dmtaylor]

No

 

[blacktop™]

Refractometers measure gravity, not alcohol.

And from what I remember, once alcohol is present, they don’t read accurately.

So basically a refractometer is good for brew day, but once fermentation has started, a hydrometer is the tool to use to measure gravity from then on.

 

[trustyrusty]

Refractometers measure gravity, not alcohol.

And from what I remember, once alcohol is present, they don’t read accurately.

So basically a refractometer is good for brew day, but once fermentation has started, a hydrometer is the tool to use to measure gravity from then on.

Thanks

 

[ianh]

Refractometers measure gravity, not alcohol.

And from what I remember, once alcohol is present, they don’t read accurately.

There are calculators that calculate the gravity from refractometers when alcohol is present. I did side by side tests between calculated refractometer value and hydrometer value for a number of years and found little difference. Hence now only use a refractometer for all gravity readings.