Calibrating a Refractometer

[grendel]

A very stupid question, but I am going nuts with this thing:

I have Pinpoint's calibration fluid, which is 53.0mS at 68 degrees.

How is this supposed to read on my refractometer, when I calibrate it?

I've been using the right side of the read out, PPT and if this thing is correct, I have so much salt in the water everything would be dead...

 

[Liquid]

I think most people use RO/DI and calibrate it to read 1.000. That's what I do.

 

[rjdudek]

You cannot use an electronic TDS calibration solution for an optical device. Use DI or distilled water and adjust to 1.00 when at the MFGs temperature compensation ref point. For my refractometer it is 1.00 at 78f. using the correct temp water makes the unit range better if it is an ATC style unit.

 

[grendel]

You cannot use an electronic TDS calibration solution for an optical device. Use DI or distilled water and adjust to 1.00 when at the MFGs temperature compensation ref point. For my refractometer it is 1.00 at 78f. using the correct temp water makes the unit range better if it is an ATC style unit.

Thanks, I called American Marine (the manufacture both the calibration fluid and my refractometer) and asked them.

Their answer was 35ppt on the standard optical refractometer.

I calibrated it and tested it against clean distilled water and it reads correctly.

 

[this is me]

I use RO/DI and set it to 1.000
I havent done it in years but everytime I check it's the same.