Seven Steps to Using a Refractometer
1. Installation of the instrument. Place the Brix refractometer in front of a table by the window or in front of an incandescent lamp. But do not place the instrument in direct sunlight to avoid rapid evaporation of liquid samples. Use a rubber tube to connect the water inlet of the thermal insulation jacket on the measuring prism and the auxiliary prism in series with the super constant temperature bath, and the constant temperature is based on the reading of the thermometer on the Brix refractometer.
2. Unlock the lock button when adding samples, open the auxiliary prism so that the frosted slope is in a horizontal position, add a small amount of acetone to the burette to clean the mirror surface, and promote the escape of difficult-to-volatilize pollutants. When using the burette, be careful not to let the tip of the burette collide with the mirror. If necessary, use lens cleaning paper to gently blot the mirror surface, but do not use filter paper. After the mirror surface is dry, drop a few drops of the sample on the wool mirror surface of the auxiliary prism, close the auxiliary prism, and tighten the lock button. If the sample is volatile, it can be added from the small tank when the two prisms are close to closing, then close the two prisms and lock the lock button.
3. Turn the handle against the light to make the indication value on the dial scale the smallest, then adjust the reflector to make the incident light enter the prism group, and observe from the measuring telescope at the same time to make the field of view the brightest. Adjust the eyepiece to make the field of view the clearest.
4. Coarsely adjust and turn the handle to gradually increase the indicated value on the dial scale until the colored light band or black and white critical line appears in the field of view.
5. Dispersion Turn the handle to make a clear critical line of light and dark appear in the field of view.
3. Finely adjust the turning handle so that the critical line is just at the intersection of the X-shaped quasi-filaments. If there is slight dispersion at this time, the de-dispersion handle must be re-adjusted to make the critical line clear and bright.
7. The reading is to protect the cleanliness of the dial. The current Brix refractometer generally installs the dial in the cover. When reading, first open the small window above the cover to let the light shine in, and then read the scale on the scale from the reading telescope. the corresponding value. Since the eyes are prone to fatigue when judging whether the critical line is at the intersection of the quasi-filaments, in order to reduce accidental errors, turn the handle and repeat the measurement three times. The difference between the three readings should not be greater than 0.0002, and then take the average value. The influence of the composition of the sample on the refractive index is extremely sensitive. Due to contamination or evaporation of volatile components in the sample, small changes in the composition of the sample will result in inaccurate readings. Therefore, when measuring a sample, it must be Samples were taken three times, the data of these three samples were measured, and the average value was taken.
