Is it possible to use a thermal mass flow meter / flow controller for other fluids?
In general, a thermal mass flow meter/controller can be used for other fluids. However, it is important that the suitability of the sealing material used for the new gas or liquid is ensured beforehand. In addition, when using a thermal mass flow meter a conversion factor must be used, as the media differ in their thermodynamic properties.
Another influencing factor is the Kv value of the valve. Using another medium affects the flow range for which the instrument was originally suited, this can change significantly.
Unlike thermal mass flow meters, flow instruments using the Coriolis or ultrasonic measuring principle, are medium independent and do not require a conversion when using other media. However, when switched over to another medium with a liquid flow instrument, the pressure drop can be different.