Rotameters are used to measure flow rates of liquids and gases. These are found in laboratory settings, as well as in the field for a variety of industries and uses. Rotameters (sometimes called rotometers) are made of three main materials: glass, metal and plastic. All have tubes and floats used for the measuring process, but the variation of materials allow for higher durability (metal) and lower cost (plastic).

Consider the environment, fluids and uses you will need the rotameter for, and then compare the different types of rotameter and decide which will work best for your business. To find the rotameter that would work for your business, you should:

1. Buy plastic rotameters to save money on bulk ordering and replacement rotameters.

2. Purchase glass rotameters for more durability still at a reasonable price.

3. Consider metal rotameters for the ultimate level of durability and accuracy.

Action Steps
The best contacts and resources to help you get it done

Find plastic rotameters to save money on bulk ordering

Plastic rotameters are comprised of the standard tube and float device. The plastic sheath allows the rotameter to be low-cost while providing high impact strength. However, these can not be used with deionized water or corrosives unless you purchase an all-plastic model, since most fittings on plastic rotameters are metal.

I recommend: Omega is a leading manufacturer of all styles of rotameters, including plastic tube rotameters. If you are ordering a combination of rotameters of various materials, complete your one-stop shopping with Omega. ERDCO is a manufacturer of a selection of flowmeters, including rotameters. They also offer a wide selection and competitive pricing.

Use glass rotameters for accuracy and precision

Glass tubes are the standard and preferred style of rotameter. They are usually made of borosilicate glass and the floats are forged from metal, glass or plastic; stainless steel is the most preferred material, though, for its anti-corrosive qualities. Glass rotameters can not be used with glass softening or distorting chemicals, like water over ninety degrees with a high pH level.

I recommend: ABB offers a selection of glass rotameters designed to fit your many fluid measuring needs. Their glass rotameters offer different levels of durability and cost. Dakota Instruments specializes in the manufacturing of glass tube rotameters of many different flow levels.

Select metal rotameters for the ultimate in durability and accuracy

Use metal tube rotameters for higher temperature and pressures. The float position is determined by magnetic fields and made of stainless steel for corrosion resistance. These are also used for steam applications, as glass tubes can not be.

I recommend: Brooks Instruments carries metal tube rotameters, listed on their site as armored variable area meters, and glass rotameters. Mass Flow Online offers an alternative to the traditional rotameters, as it is digital with a hard exterior casing.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Ask for bulk ordering discounts, add-on warranties and repair options when purchasing rotameters.