A portable ultrasonic flow meter does well for temporary measurement and verification of in-line flow meters. However, it only has an accuracy of around two percent – not enough to calibrate another meter with better accuracy.
Now, the market has transit time and Doppler flow meters for your purposes. You need to check your fluids to decide which will work better for you.
You shouldn’t have any trouble installing a portable ultrasonic flow meter as long as you choose one based on necessary information like sound velocity, pipe size and thickness, and so on.
If you work in field service, then you need a bunch of sensors to cover different pipe sizes. But if you work with similar pipe sizes, then you’ll need fewer sensors to cover most applications.
On the right sidebar there, we have some products that you can scale out to see what works for your application. You’ll see companies such as Endress+Hauser, GE, and Fleximum. All of them have a broad range of pipe sizes and temperatures. You probably can find one to cover everything you need.