The use of glass measuring pipette
Measuring pipette is commonly used in laboratory glass measuring device, usually made of sodium calcium glass, a complete measuring pipette should have a dividing line, nominal capacity, type mark, standard temperature (20℃), accuracy level, trademark or factory name and other marks! The dividing line and the value of the quantity should be clear, complete and durable, and the specific requirements should meet the current national standards.
The use of measuring pipette:
measuring pipette is a kind of precision liquid measuring instrument. Pay attention to the following points in use:
1. Before use:
①Observe whether the measuring pipette is damaged or stained.
② Observe the size of the measuring pipette: the size of the measuring pipette should be equal to or approximately equal to the volume of the solution to be absorbed. (3) Observe whether there is “blowing” word: if there is, it indicates that the scale is reached, and the solution should be blown out after putting the liquid, otherwise it will not be blown.
2, holding method: thumb and middle finger pinch measuring pipette, index finger free.
3, take liquid: ① vertical into liquid ② medium into liquid depth ③ ear ball suction ④ take liquid height higher than the scale 2-3cm⑤ Index finger on the upper end of the measuring pipette ⑥measuring pipette lift from the liquid level ⑦ Observe no bubbles in the liquid ⑧ filter paper wipe tube wall.
4, put the liquid to the scale: ① measuring pipette vertical ② the right eye is parallel to the scale line ③ gently loosen the index finger (turn the measuring pipette), so that the liquid level is slowly lowered until the lowest point is tangent to the scale line.
5, put the liquid to the container: ① measuring pipette vertical ② container tilt 45℃③ make the solution flow into the container naturally, pay attention to blowing and not blowing.
6, a measuring pipette only absorb one reagent, immediately immersed in water after use.
Measuring pipette reading method:
1. Keep the measuring pipette vertical when suction and reading.
2, keep the liquid level and eyes into a horizontal line when reading.
3, the liquid in the measuring pipette due to surface tension will form a concave surface, reading to take the value of the bottom of the concave surface.
Additional knowledge: measuring pipettes are graduated in a variety of volumes, the same side can draw different volumes.
Post time: Nov-05-2021
