Volumetrix flask how to#

However, the disadvantage is that its use is determined solely by the transfer of that specific amount of liquid. This feature is an advantage in terms of the precision and accuracy of the liquid transferred. That is why there are different sizes according to the need of the technician. This ampoule is calibrated for a specific volume that is, it can only be used to transfer the indicated and calibrated volume in the pipette. The characteristic that differentiates it from the rest is that in its central part it usually presents a bulge or blister in the cylinder, and subsequently a narrowing in the lower part. However, it has some specific characteristics: Ampule in the cylinder The volumetric or volumetric pipette is also the rest of the pipettes, a transparent glass cylinder with its conical bottom end.

Volumetrix flask how to#

3.1 How to calibrate the volumetric pipette?.3 Calibration of the volumetric pipette.1.4 Does not require the use of the mouth.This means that in a pipette with a volumetric capacity of 2 ml, the expected limit of error is 0.01 ml in class A pipettes and 0.02 ml in class B volumetric pipettes. The capacity error data is tabulated as follows: Errors by capacityР”В¬apacity error refers to the known РІР‚Сљlimit errorРІР‚Сњ based on the volume capacity of the pipette being used. They are marked with the words РІР‚СљTCРІР‚Сњ, РІР‚СљcontРІР‚Сњ or РІР‚СљinРІР‚Сњ.Р’В This means that the volume indicated on the pipette corresponds exactly to the volume of liquid contained in the pipette Р’В that is, before emptying. They are marked with the words РІР‚СљTDРІР‚Сњ, РІР‚СљvertРІР‚Сњ or РІР‚СљexРІР‚Сњ.Р’В This means that the volume indicated on the pipette corresponds exactly to the volume poured by the pipette.Р’В The liquid that adheres to the walls has already been taken into consideration when performing the calibration. Volumetric material can be found with two types of calibrations: Calibrated for pouring To calibrate a pipette requires a very clean and thorough technique.Р”РЋ- The pipette is cleaned and dried thoroughly to avoid errors in the readings.Р”Сћ- Place distilled water in an Erlenmeyer flask and leave it at room temperature for 15 minutes.Р’В Then the temperature of the water is measured.Р”Р€- A beaker is weighed on a scale and the weight is notedР’В , with an error of one tenth of a mg.Р”В¤- Using a propipette, fill the pipette with the water contained in the Erlenmeyer flask and transfer the water to the beaker.Р’В Subsequently, the glass is weighed again and the mass of the transferred water is calculated.Р”В¦- The average of the four pipette measurements is calculated and determined.Р”В§- The density of the waterР’В is calculatedР’В at the temperature of the first measurements, as well as the average of the volume of the water. The volumetric material is calibrated to transfer a certain volume at a certain temperature, which is normally standardized at 20 Р’В° C. In case of having only one capacity or mark above the ampoule, it means that the pipette must be flush up to that mark so that, when emptying it, it dumps the volume that indicates the capacity of the pipette on the outside.Р’В Wait 15 seconds after the last drop falls.Р”Р‡or example, if a volumetric pipette is used that indicates written on the glass that it has a capacity of 20 ml and with a single capacity above the bulge, it means that the pipette must be filled up to that mark so that, once it has been completely emptied into the container to be transferred, the volume transferred is exactly 20 ml.Р”В¬alibration is the process by which the precision of the pipette is established.Р’В It is the degree of correspondence between the value that the instrument indicates that it is transferring, with the value that is actually transferred. This feature is an advantage in terms of precision and accuracy of the transferred liquid.Р’В However, the disadvantage is that its use is determined solely by the transfer of that specific amount of liquid. This ampoule is calibrated for a specificР’В volumeР’В Р’В that is, it can only be used to transfer the indicated and calibrated volume into the pipette.Р’В That is why there are different sizes according to the need of the technician.