Questions about measuring salinity.

Robin

Good day to everyone. I have encountered a problem. Recently, I bought a refractometer (the cheapest Chinese one). I salted new water and heated it to 25 degrees. I took a measurement. The refractometer showed 1.026, while a glass Aquamedic salinity meter showed 1.020. Who should I trust? How else can I check?

George5104

Buy Salifert calibration solution. Calibrate the refractometer. If there is no calibration, check both with this solution and determine who is lying and by how much. If there are jewelry scales and a measuring laboratory graduated cylinder, prepare the solution yourself. Prepare the solution using osmosis or pharmaceutical distillate.

Cynthia

Where can I buy Salifert calibration solution?

Laura4892

Here

Gregory9432

You can check the aquamedic by osmosis; it should show 0, but in reality, the readings will differ, mine is off by 4 divisions. For the refractometer, you can prepare a calibration solution from regular table salt, 36.5 grams + 963.5 grams of osmosis = a solution of 35 parts per thousand.

Jerry

and even better to buy it at the pharmacy. 1000 density, 0 salinity.

John3187

I bought Salifert. I calibrated it. Thanks to everyone for the advice. But still, the Aquamedic hydrometer shows a different measurement. When the refractometer shows 1.026, the hydrometer shows 1.020. That's how it is.

Katie3017

The hydrometer is 100% lying. Look at what it shows in osmosis instead of 1.000. It should also be noted that for measurements with a hydrometer, the temperature must be 25 degrees; otherwise, the error will be about 0.3 divisions, plus or minus. But it is stable; you just need to calculate the correction once, and you never have to calibrate it again.

Frank7213

Are the units of measurement exactly the same? There is density, and there is SG; a hydrometer shows density, and a refractometer shows SG. Density 1.024 = 1.026 SG, if I remember correctly. In general, pay attention to the units of measurement indicated on the instruments.