Your search for "radiometric mass flowmeters" revealed the following:

Endress+Hauser OUSAF11 NIR VIS absorption sensor
Endress+Hauser OUSAF11 phase detection sensor
Yokogawa EJX110A Differential Pressure Transmitter
Yokogawa EJX110A DPharp digital sensor differential pressure transmitter
Yokogawa EJA130E Differential Pressure Transmitter
Yokogawa EJA130E DPharp digital sensor differential pressure transmitter
Yokogawa EJXC40A Digital Remote Sensor DRS differential pressure system
Yokogawa EJXC40A DRS system with high-side and low-side digital pressure sensors
Endress+Hauser FHG65 Gamma Modulator
FHG65 Gamma Modulator by Endress+Hauser
Fluke 51 II Handheld Digital Thermometer with thermocouple probe
Endress+Hauser Ceraliquid CPS41 analog pH sensor
Endress+Hauser CPS41 analog pH sensor front view