News — Serum Protein Refractometer

This Guide Is Not Just for One Brand of Refractometer

Although National Industrial Supply sells and services a wide variety of handheld clinical and veterinary refractometers, the basic operating principles covered in this guide apply to many brands and models of optical veterinary refractometers.

Whether your instrument is a MISCO, Atago, Reichert, Heska, Westover, JORVET, American Optical, Schmidt + Haensch, or another manufacturer, you will generally encounter the same fundamental concepts: properly calibrating the instrument, focusing the optical system, applying an adequate sample, selecting the correct species-specific scale, interpreting the light/dark boundary, and cleaning the prism between measurements.

There can be important differences between manufacturers and individual models, particularly regarding calibration procedures, temperature compensation, available scales, cleaning instructions, sample volume, and acceptable operating temperatures. Your manufacturer's instructions should always take precedence when they differ from the general procedures described here.

The reason we created this guide is simple: we hear from veterinary technicians using refractometers from all kinds of manufacturers. Many of the questions are remarkably similar—"How do I calibrate this?" "Which line do I read?" "Why is my reading blurry?" "Do I need to clean it between samples?" "Why doesn't my water read 1.000?"

If you are holding a veterinary refractometer that is new to you, we hope this guide gives you the practical foundation you need to understand what the instrument is doing and how to get consistent readings from it.

In fact, published veterinary research has compared multiple refractometers—including American Optical, Reichert, Heska, MISCO, Atago, and other optical and digital instruments—showing why understanding both the instrument and the measurement technique is important. Different instruments can produce somewhat different readings, even though several commonly used veterinary refractometers have demonstrated strong agreement for canine urine specific gravity. PubMed

So if you didn't purchase your refractometer from National Industrial Supply, that's perfectly fine. This information can still help you learn how to use it. Our objective is to make the process less intimidating and help veterinary professionals get the most reliable measurement possible from the instrument they have in front of them.