VaisalaDryCap®技术

The DRYCAP story began in the mid-1990s following an unresolved measurement challenge. Traditional humidity instruments were not accurate enough at very low humidities, while commonly used aluminum oxide sensors were prone to drift and required frequent calibration. There was a strong demand for accurate, easy-to-use, cost-effective, and low-maintenance dew point instruments.

Vaisala's solution was to combine the highest quality polymer technology with a patented key feature – auto-calibration – that would eliminate sensor drift in very dry conditions. In 1997, Vaisala introduced a a new type of露点基于薄膜聚合物技术的传感器，DryCap®传感器。自推出以来，Drycap产品家族已经成长为涵盖了各种应用，从干燥过程到压缩空气和干室。Drycap传感器特别以其在炎热和非常干燥的环境中的可靠性能而闻名，而这一非常成功的创新如今仍在进行。

How it works

DRYCAP’s unrivalled performance is based on two innovations: the proven capacitive thin-film polymer sensor and the auto-calibration function. The sensor’s thin-film polymer absorbs or releases water vapor as the surroundinghumidityincreases or decreases. The dielectric properties of the polymer change as the humidity around the sensor changes, as does the capacitance of the sensor. Capacitance is converted into a humidity reading. The capacitive polymer sensor is bonded together with a temperature sensor, and dew point is calculated from the humidity and temperature readings. Vaisala’s patented auto-calibration function optimizes the measurement stability in dry environments. The sensor is heated at regular intervals during the automated auto-calibration procedure. The humidity and temperature readings are monitored as the sensor cools to ambient temperature, with offset correction compensating for any potential drift. This enables the DRYCAP sensor to deliver accurate measurements in the long term, dramatically reducing the need for maintenance.

露点测量的典型应用

Vaisala Drycap露点仪器在工业应用中测量露点，其中气体湿度通常非常低。露点通常是一个关键参数，控制不足会导致流程停机时间，流程设备损坏和最终产品质量恶化等问题。露点是在各种干燥和热处理过程中测量的塑料干燥,baking ovens，和food drying。它也受到控制压缩的空气，在多余的水分会导致终端产品质量，冰形成和设备腐蚀的情况下。其他典型应用包括医疗气体，干燥环境lithium battery manufacturing，和gas-insulated high-voltage equipment used in the power industry.