The first refractometer I’ve used was the Atago N1. The basic prism refractometer capable of determining sugar content from zero up to 32 degree Brix. Any liquid with higher sugar content will just give a blue screen reading. A blurred version of Windows Blue Screen of Death, without the white fonts.
Here is another Atago refractometer version. The Atago HSR-500, capable of reading 0 to 90 degree Brix. Wow! what a wide range.
I found using it a bit tricky. I couldn’t get any proper reading at first.
In case you have these model, here are few usage tips that can make your laboratory life a little easier.
Part 6 – the eyepiece. Turn it either clockwise or counterclockwise to get a clear view of degree Brix scale. People vision vary, set it for your own eye before use.
Part 7 – range selector. Turn it to suit expected sugar content of sample to be analyzed. Set to 1 for 0 to 42. Set to 2 for 42 to 71. Set to 3 for 71 to 90. If a proper reading could not be gathered, try setting it to a different number.
Part 2 – main prism. Place few drops of liquid here and close the cover carefully and slowly. Wipe off any excess on the sides.
Par 4 – the color eliminating ring. After setting the part 6, try to get a clear vision by rotating this ring. Notice the line getting clearer or more blur as you rotate this.
Part ? – the light window. Point this part to a light source while reading. It can be a sunlight, flashlight or a fluorescent bulb. Take my word, you really need a good light source for this.
Part 3 – the supplementary window cover. If the liquid sample is turbid, block the part ?, open this and point to light source.