Refractometer differences

[Macrosill]

I see Ebay has some refractometers listed. Some of them are listed as Aquarium, Automotive anitfreeze and ... Are these all the same with different labeling? Do they measure different levels? Can they be interchanged?

Thanks,
Brian

[fishfreek]

Very different.

They have different crystals in them. The resturant business even has a refractomoter to calibrate their soda machines.

As you may be aware water has a particular refaction index. Antifreeze, soda and syrip will also have a differnet refraction index so using an antifreeze refractomoter will not turn up much results for saltwater.