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The existing measurement methods include: 1. Electrolytic method. Phosphorus pentoxide sensors utilize the principle of electrolyzing water molecules into hydrogen and oxygen. Advantages: high sensitivity, suitable for detecting very small amounts of water/traces of water, and they can also measure corrosive gases. Disadvantages: The sensor requires regular repainting, has significant drift, and is susceptible to the influence of background gases such as H2 and O2. It has a long equilibration time and slow response. The resistance-capacitance method (capacitance method) utilizes a high-purity aluminum rod whose surface is oxidized to form an ultra-thin layer of alumina; a porous network-like gold film is then applied on top of this layer. A capacitor is formed between the gold film and the aluminum rod. Due to the water-absorbing properties of the alumina layer, the capacitance value changes depending on the amount of moisture in the sample gas, and by measuring this capacitance value, it is possible to determine the humidity of the sample gas. The main advantage of this method is that its measurement range can be as low as -100°C; another notable advantage is its very fast response speed – the response from dry to wet conditions can reach 90% within one minute – which makes it suitable for use in field applications and situations requiring rapid measurements ； The disadvantage is poor accuracy, with an uncertainty of typically ±2 to 3°C. However, through the continuous efforts of various manufacturers, this method is gradually being improved. For example, the stability of sensors has been **enhanced** by changing materials and improving manufacturing processes, and saturation linearity has been achieved through compensation of the sensors’ response curves, thereby solving the problem of automatic calibration. Advantages: Fast response time. Disadvantage: Poor accuracy. (Measured in gaseous state) III. Capacitance tomography (capacitive method) l Principle of capacitance tomography component measurement technology: Correflow capacitance tomography technology involves installing several electrodes on the inner wall of the sensor to measure the capacitance of the internal space, and calculating the volume fraction occupied by solids based on the differences in dielectric constants of different phases. To eliminate the impact of the uneven distribution of particles within the pipeline on the calculations, this technique employs a rotating electric field to sequentially activate each electrode, thereby determining the capacitance distribution in all directions within the internal space; volume ratios are then calculated accurately using capacitance tomography. By utilizing a unique phase-locked amplification technique, the amplitude and phase difference of the response signal are measured at multiple excitation frequencies, thereby allowing for the accurate calculation of both the equivalent dielectric constant and loss factor of the mixture. The water content is then determined using calibration curves at different temperatures. Capacitive sensors are widely used in various industrial fields. From the perspective of the composition of the electrode and the measurement circuit, industrial capacitive sensors can be divided into two main categories: grounded capacitive sensors and floating capacitive sensors. Product advantages: ü Real-time monitoring of the trace water content in organic substances on a ppm level; for example, measurement of water content in ethylene glycol (0-1000 ppm) and chloromethane (0-1000 ppm). Ü A more reliable design, with the sensor part plated in pure gold, which eliminates the problem of drift caused by unstable materials ； ü The entire instrument is explosion-proof, enabling moisture measurement in explosive environments ； ü Passive contactless sensing, no moving parts, no pressure loss, no obstruction to flow, no risk of material contamination ； ü In explosion-proof environments, compared to the pull-out measurement method which results in numerous leakage points, in-situ embedded installation is used to ensure greater safety during use and maintenance ； ü It uses ultra-high-precision capacitive sensors, which offer strong interference resistance, ensure stable measurements, and prevent signal drift due to temperature changes ； ü It utilizes the capacitance principle; the precision of the capacitive sensor reaches 5 aF, which is 20 times higher than that of similar capacitive sensors ； ü Phase-locked amplification technology and multiple excitation signals are used to ensure accurate capacitance measurement ； ü Use dielectric temperature compensation 1 to ensure accurate capacitance measurement at different temperatures ； ü Medium temperature compensation 2 and a proprietary algorithm are employed; by taking advantage of the different variations in the dielectric constant of various substances under different temperature conditions, it is possible to accurately determine the proportion of that substance within the overall mixture ； ü Core sensing measurement technology based on fluid/statistical models and digital signal processing, with high sensitivity ； ü Excellent stability, reliability, and repeatability ； ü Excessive signal sampling and optimization algorithms to eliminate random disturbances caused by unstable flow ； ü Unique circuit and algorithm design to eliminate spatial electromagnetic interference ； Compared with other measurement methods, capacitive tomography directly measures trace amounts of water in organic liquids, is unaffected by impurities, and should be widely used