How does a blood glucose meter work and how do I use it?
1. Working principle of sugar meter
When light enters another medium from one medium, refraction occurs, and the ratio of the sine of the incident angle is constant. This ratio is called the refractive index. The soluble solid content in fruit and vegetable juices is directly proportional to the refractive index under certain conditions (same temperature and pressure). Therefore, by measuring the refractive index of fruit and vegetable juices, the concentration (sugar content) of fruit and vegetable juices can be found. Commonly used instruments are handheld refractometers, also known as sugar mirrors and handheld sugar meters. By measuring the soluble solid content (sugar content) of fruits and vegetables, the quality of fruits and vegetables can be understood and the maturity of the fruits can be roughly estimated.
Handheld sugar meters are generally cylindrical in shape.
2. Instructions for use of handheld sugar refractometer
(1) How to use
Open the cover and carefully wipe the detection prism with a soft cloth. Take a few drops of the solution to be tested, place it on the detection prism, and gently close the cover to avoid bubbles and allow the solution to spread on the surface of the prism. Aim the light entrance plate of the instrument at the light source or bright place, observe the field of view through the eyepiece, and turn the eyepiece adjustment handwheel to make the blue-white dividing line of the field of view clear. The scale value of the dividing line is the concentration of the solution.
(2) Calibration and temperature correction
The instrument needs to be calibrated to zero before measurement. Take a few drops of distilled water, place it on the detection prism, and turn the zero adjustment screw to adjust the dividing line to the 0% position of the scale. Then wipe the detection prism and perform detection. Some models of instruments require standard solutions instead of distilled water during calibration.
Another method (only suitable for measuring sugar content) is to use a temperature correction table and add (or subtract) the temperature correction value to the value read at ambient temperature to obtain an accurate value.
(3) Things to note
The instrument is a precision optical instrument. The following matters should be paid attention to during use and maintenance:
1. You must be careful during use and use it strictly according to the instructions. Do not loosen the connecting parts of the instrument at will. Do not drop or collide. Violent vibration is strictly prohibited.
2. After use, it is strictly forbidden to put it directly into water for cleaning. It should be wiped with a clean soft cloth. The optical surface should not be bumped or scratched.
3. The instrument should be stored in a dry place without corrosive gas.
4. Avoid the loss of spare parts.
