Does an outdoor flue gas pressure transmitter require heating?

Whether heating is required for the transmitter depends on the outdoor temperature; if it is lower than the operating temperature, then heating is definitely necessary.

Are you referring to the pressure transmitter in the CEMS installed on the chimney? Generally, the flue gas pressure in CEMS systems is measured using integrated measurement tubes located on the flue gas sampling platform; simultaneously, the flow rate and temperature of the flue gas are also measured there. A sampling tube extends into the chimney, with it being required to reach about halfway down, so such tubes are usually installed at a relatively high position ； The sampling tube is used to carry the flue gas to a local measurement box for direct measurement; generally, heating is not required, but in conditions of extremely low external temperatures, the measurement box needs to be heated to prevent condensation. It is generally not necessary, as the flue gas temperature is usually above 100 degrees, and the sampling tube is only a few meters long; therefore, the gas does not condense quickly when it is drawn out.

Generally, a CEMS chamber is installed below the chimney, at some distance from the sampling point; CEMS manufacturers usually provide their own heating systems. You can clarify this with the manufacturer when making the purchase. If you are the manufacturer, then why not equip it? The cost increase for you is minimal, and the system becomes more stable as well.