GE HT400 is targeted at high-temperature working conditions that conventional humidity transmitters cannot adapt to, widely matched with compressed air systems, drying ovens, thermal treatment flue gas and high-temperature pipeline gas detection. The model HT400 marks its core feature of supporting continuous stable operation under up to 200 ℃ medium temperature, breaking the temperature limit of ordinary RH sensors.

The core measuring element adopts high-stability modified polymer capacitive sensitive film. The dielectric constant of the polymer layer changes synchronously with ambient water vapor concentration, and the internal circuit converts capacitance signals into real-time relative humidity (0~100%RH), medium temperature and calculated dew point values. The sensor features fast response speed, strong anti-pollution ability against oil mist and tiny dust, and can automatically recover measurement accuracy after temporary condensation immersion without permanent failure of the sensitive chip.

The probe wetted structure is made of high-temperature resistant 316L stainless steel, equipped with high-temperature resistant sintered metal protective filter head, which blocks solid impurities from wearing the sensitive layer while ensuring smooth penetration of water vapor. The whole probe body uses high-temperature resistant sealing filler and high-temperature wire, no air leakage or signal drift occurs under long-term high-temperature thermal radiation and alternating cold and hot working conditions. The main transmitter housing complies with IP65 protection grade, suitable for installation in high-temperature pipe galleries, oven exhaust pipelines and thermal equipment peripheral sampling ports.

The instrument adopts standard two-wire loop-powered 4–20mA output mode, one loop cable completes power supply and signal transmission simultaneously, which greatly simplifies field wiring construction. The measured humidity and dew point data can be directly connected to DCS, PLC and SCADA industrial control systems for remote real-time monitoring and over-limit alarm interlock configuration. Built-in digital temperature compensation algorithm automatically offsets measurement deviation caused by high-temperature environment thermal drift, guaranteeing stable measurement accuracy within the full temperature range.

Each GE HT400 transmitter is calibrated for RH linearity and dew point calculation before factory delivery with standard humidity generating equipment. There are no mechanical moving parts inside the electronic module, daily maintenance only needs regular inspection of the front filter for blockage and periodic calibration verification according to site pollution severity, with low long-term operation and maintenance cost. It has passed general industrial EMC electromagnetic compatibility certification, effectively resisting interference from surrounding heating equipment, frequency converters and high-power electrical equipment.

Main application scenarios cover hot compressed air drying systems, food high-temperature baking tail gas, industrial kiln protective atmosphere, chemical high-temperature process gas humidity monitoring and other high-temperature working environments, being a mainstream economical high-temperature humidity measuring device in the industrial gas analysis field.