How to choose the right method of dosage for your fluid process

Gravimetric vs Volumetric

Ensured accuracy in the fluid dispensing or dosing system is critical to the success of many processes and experiments—from making sure the right amount of crushed tomatoes is added in a spaghetti sauce recipe to dispensing life-saving vaccines into vials. Although the critical volumes in these applications are different, they both rely on some method of metering products with some amount of measurable accuracy. The first step in bringing accuracy to a fluid dispensing system, before even purchasing a pump, is to determine what accuracy is tolerable to your process or experiment. As the above applications illustrated, a lost drop of tomato liquid is not as impactful as a lost drop of vaccine.

Accuracy only follows measurability, so once a tolerance for dispensing accuracy is determined, choose a pump with a measurable output mechanically tied to the motor RPM, otherwise known as a metering pump. Choosing a metering pump such as a peristaltic or diaphragm system is a step in the right direction because metering pumps provide a reliable pattern of “fluid pockets” per revolution. The pump output can be determined mathematically using the volume of the fluid displaced and the motor RPM. Accuracy and resolution of the motor RPM is critical, so choose a pump drive within your determined tolerance for dispensing.

What about extra drops?

If you are concerned about extra drops into your end product or container, here are some quick solutions:

Make sure the tubing is clean. Buildup can affect the cohesive forces creating a welcoming surface for droplets.
Install a filling nozzle. Although the above still applies here, these nozzles are easier to clean and their geometry makes droplets more predictable, therefore easier to control.
Use a Masterflex pump. Masterflex pumps manufactured today feature anti-drip technology which briefly reverses the motor at the end of every dispense cycle (rotation customized by the user).

If your application requires a different pump technology, the Masterflex drives with Quattroflow^™ pump heads, Masterflex piston pumps, and Masterflex gear pump are all compatible and enhanced by the robust variety of Masterflex tubing formulations so the systems can be used in almost any dosing or metering application.