The handheld refractometer is an instrument that uses the principle of refraction of light to detect the content or concentration of soluble substances in a liquid. Any solution that uses the refractive index as a product index can be measured by a handheld refractometer. At present, it has been widely used in the determination of the concentration of tomato paste and other jam. Determination of milk, sugar, honey concentration, determination of the concentration of sodium glutamate solution in the production of monosodium glutamate concentration and crystallization process, black liquor concentration, can also be used for direct measurement of "concentration changes of three glue production on glue. The refractometer can be directly installed on the pipelines or tanks of the production line, and the detected substances can be detected, and it can be automatically controlled by adjusting the system according to the given value.
The handheld refractometer uses the principle of full reflection of light, and the light emitted by the light source. After concentrating system converged onto the measuring prism and the measured fluid interface, when measuring the rate of refraction prism is greater than or equal to the measured liquid refractive index, total reflection phenomenon occurs, the critical angle of total reflection of the size concentration determined by the measured refraction glue rate, greater than the critical angle all the light reflected to the light battery (photoelectric conversion element), showing "bright", less than the critical angle of light refraction was measured to most of the gum liquid, showing dark areas in the light of the battery". Glue concentration has a certain position of the "light" and "dark" boundary demarcation line in the photocell position varies with the concentration of glue solution, namely the photocell light area and light battery output voltage and glue concentration, which can measure the glue according to the concentration of the output voltage of photovoltaic cell.
A total of two light battery group than light battery and micro light battery, in the measuring range refractometer, terminator mobile in measuring light battery, reference light battery is always in the bright area, output voltage of two light battery group sent to the electronic potential instrument two times difference measuring system meter.