How to Measure Air Flow Rate–Not As Easy As it Appears

If we look at what is considered low flow measurement of air mass flow rate,  those applications ranging from 0 to 10 sccm up to 0 to 1000 slpm ranges, there is a right way and a wrong way to measure. It’s an inherent problem many of our customers face before they find the right solution in a quality mass flow meter or controller. After all, you have to consider pressure and temperature variation, contaminates, and the fact that everything is occluded by metal pipes and difficult to see. In short, measuring air mass flow rate is often easier said than done.

First and foremost, you need to consider what technologies are appropriate for your application. If you find what you think is the perfect flow solution, but it’s described as “affordable,” you probably want to be somewhat skeptical—if it sounds too good to be true, it probably is! These can be cheap knock-offs of technology pioneered and mastered by another.

Fortunately, Sierra offers a variety of mass flow meters and controllers specifically designed for use with CDA, XCDA, XCHA. Be it laboratory, OEM, tooling, or just compressor output monitoring, Sierra thermal meters use live condition compensation, digital compensation, and thermal energy transfer anemometery to deliver solid-state sensing solutions. A few advantages of Thermal Mass, featuring high turndown, no moving parts, and direct mass flow rate measurement (instead of inferred) are:

• No buffeting due to rotoblades


• No particulate shed


• Inherent temperature and pressure compensation


• Application operation flexibility


• High accuracy

Orifice plates, rotometers, and VTP devices cannot match the intrinsic accuracy of bypass flow capillary thermal anenometers! Choose from multiple tiers of accuracy, complexity and priced to match your demands. Contact us today for the right flow solution for your application.