There are two typical versions of an acrylic rotameter. The first is an acrylic tube model where the flow body is made of plastic and the meter is the shape of the circular flow body. The second kind is a “pillar” of acrylic where the meter body is essentially rectangular in shape, even though the flow tube within the meter is circular.
Acrylic rotameters often offer the advantage of being compatible with media that may be more aggressive or chemical in nature. Because plastic is less expensive than metal, acrylic flow meters are often cheaper than their metal constructed counterparts.