The measuring cylinder is a kind of measuring device used in laboratory. It is made of glass. Its purpose is to take liquid quantitatively according to volume. It is a vertical long cylindrical shape with a mouth on one side of the upper edge for easy dumping. The lower part has wide base to maintain stability. The cylinder wall is engraved with a volume range for users to read volume. The maximum measured volume ranges from ml to l. The cylinder wall is marked from bottom to top. Outer wall calibration is based on ml. 10 ml cylinder is 0.2 ml interval, while 50 ml cylinder is 1 ml interval. The bigger the measuring cylinder is, the thicker the diameter is, the smaller the accuracy is, and the larger the reading error caused by the deviation of the line of sight is. When observing the readings, the experimenter should pay attention to the need for eyesight to be equal to the lowest point of concave liquid level (or the highest point of convex liquid level).
1. When the liquid is injected into the cylinder, use the left hand to hold the measuring cylinder, tilt the measuring cylinder slightly, and hold the reagent bottle in the right hand, so that the bottle mouth is close to the measuring cylinder mouth, so that the liquid flows slowly.
2. The measuring cylinder has no "0" scale. Generally, the starting scale is 1/10 of the total volume. In many chemical books, the scale of the measuring cylinder is back to people, which is very inconvenient. Because the line of sight must pass through two layers of glass and liquid, if the liquid is turbid, the scale will be even more difficult to see, and the scale number is not pleasant to the eye. So the scale is good to face to people.
3. After injecting the liquid, wait for 1-2 minutes to make the liquid attached to the inner wall flow down, and then read out the scale value. Otherwise, the read value is too small.
4. The calibration of measuring cylinder surface refers to the volume at 20℃. With the increase of temperature, the cylinder will expand and the volume will increase. Therefore, the measuring cylinder can not be heated, nor can it be used to measure superheated liquids, let alone chemical reactions or preparation of solutions in the measuring cylinder.
5. If only to make the measurement accurate, it is not necessary to flush the measuring cylinder with water, because the residual liquid has been taken into account when manufacturing the measuring cylinder. On the contrary, if flushing, the volume will be larger. If you want to measure other liquids with the same measuring cylinder, you must wash them with water to prevent contamination of impurities.
Stopper: with glass stopper, w/o stopper
Base: round base, hexagonal base
With spout and printed graduation,round base, (hexagonal base optional)
With ground-in glass stopper, with spout and printed graduation,round base,(hexagonal base optional)