Accurate fountain solution testing helps offset printers maintain consistent press performance. Learn how a BOSS Refractometer can help check the concentration of freshly mixed fountain solution, why readings must be calibrated to the specific concentrate, and how refractometry compares with pH and conductivity testing. Discover the limitations of testing used fountain solution and practical steps for more reliable measurements.

Discover how the RGM-100 Gem Refractometer measures gemstone refractive index. Follow step-by-step instructions for preparing a stone, applying contact fluid, reading the RI scale, examining double refraction, and maintaining your instrument.

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.

Measuring Invert Sugar with a Refractometer: Brix, Applications and Choosing the Right Instrument

Invert sugar is used throughout the food and beverage industry, particularly in applications where controlling sweetness, moisture, texture, shelf life and crystallization matters. From confectionery and baked goods to beverages, jams, syrups and pharmaceutical products, manufacturers need a practical way to monitor the concentration of sugar solutions during production.

One of the simplest analytical tools for this purpose is a refractometer.

Refractive index is a fundamental property used to identify substances, evaluate purity, measure solution concentrations, and monitor quality in pharmaceutical, chemical, food, and laboratory applications. This guide explains the science behind refractive index, Snell’s Law, specific refraction, and molar refraction, including the Lorentz-Lorenz equation and its relationship to molecular properties. Learn how an Abbe refractometer determines refractive index and why measurements are commonly standardized at 20°C using the sodium D-line at 589 nm. We also explore how modern digital refractometers simplify rapid, repeatable analysis for pharmaceutical quality control, chemical testing, sugar and alcohol measurements, and other laboratory applications. Understanding temperature, wavelength, calibration, and measurement accuracy is essential for obtaining reliable refractive-index results.