A conventional handheld refractometer is an analogue tool designed for the measurement of the refractive index of a liquid substance. It operates through the critical angle principle, wherein the lens and prisms will project a shadow line onto a small glass reticle found inside the instrument. The user of the device will view it through a magnifying eyepiece. The practical use of a refractometer comes in the form of placing a sample between a measuring prism and a cover plate. The light that travels through the sample will pass through the reticle or gets internally reflected. The net effect comes in the form of a shadow line created between the dark and illuminated area. It is the same area where the shadow line will cross the scale, and reading becomes possible.
Know that because the refractive index depends on temperature, it is critical that the use of a refractometer must come with automatic temperature compensation. The way to achieve that is by using a small bi-metallic strip which moves a prism or lens to act as a proper response to the temperature changes. Nowadays, when you are hoping to buy this instrument, you should know that it is not merely about the hand held refractometer price. The truth is you first must have a comprehensive understanding of what a traditional and digital handheld refractometer has to offer.
The digital variant of the handheld refractometer is specifically designed for the measurement of the refractive index of materials. You expect that the device will operate or function in the same general critical angle principle to that of the conventional refractometer. Well, there also is no denying that there are differences. For instance, the light used in the digital variant is from an LED light source focused on the underside of the prism element. Hence, when the liquid sample is applied to the prism’s measuring surface, a portion of the light will be transmitted via the solution and will eventually get lost. Meanwhile, the remaining light is reflected onto a linear array of photodiodes, thereby creating a shadow line in the process.
When you are comparing hand held refractometer price on the market, you first must acknowledge that digital handheld variants are usually more precise when compared to a traditional handheld variety. However, they also are less accurate if you compare them to benchtop refractometers. As a first-time user, you may find it surprising that the digital variant requires a considerably more substantial amount of sample to come up with an accurate reading merely because the sample is not spread thinly against the prism. Results may be shown in different units of measurement, including that of boiling point, freezing point, brix, concentration, and others. You must choose one with features automatic temperature compensation.