HC105 / HC109
The HC Series of E+E Elektronik are capacitive humidity sensors produced in thin film technology. Due to careful selection of materials, state-of-the-art production technology and long experience of E+E in thin film technology, all HC humidity sensors show an excellent long term stability, highest reproducibility of the sensor characteristic, are wettable and very resistant to pollutants.
They are used in all E+E standard transmitter series, as well as in a large number of customized and OEM products from mass- to high-end applications.
The excellent linearity enables the use of a simple, cost-effective oscillator circuitry with an easy and accurate calibration procedure.
Extensive evaluation results such as from various long term tests or resistance to most chemicals of practical importance are available.
A capacitive humidity sensor is in fact a plate capacitor. A polymer layer is placed between a metal electrode and a coated glass substrate. The dielectric permittivity e of the polymer depends on its water content.
schematic construction of an E+E humidity sensor
For an optimal humidity exchange between the polymer layer and the surrounding air, the metal electrode is a porous layer of 0.1 to 1 µm produced by a special production process. The absence of additional insulation layers leads to a high sensitivity. (refer to characteristics of E+E humidity sensors)
The capacity of the sensor:
The working range is the maximum range for humidity and temperature wherein specified data and tolerances are valid. The interdependence of humidity and temperature is of importance. (refer to data for working range).
The nominal capacitance is the capacity of the sensor at a certain relative humidity, at temperatures of 20°C or 30°C and operating frequency of 20kHz.
The sensitivity is the variation of the capacitance per %RH. It is measured at 33 %RH and 76 %RH.
The linearity error is the maximum deviation of the sensor characteristic from the best linear approximation.
The hysteresis is the maximum difference between two cycles 15 – 95 %RH and 95 – 15 %RH. The cycles are performed in steps of 10 %RH with a stabilization time of 1 hour after each step.
The temperature dependence is the deviation in % RH per °C at different humidity and temperature values.
Response time t90
The response time t90 is the time the sensor needs to reach 90 % of the final value for a 0 – 80 % step of relative humidity.
The loss tangent quantifies the resistive value of the impedance. It is measured at 25 °C, 76%RH and at operating frequency 20 kHz.
Maximum Supply Voltage
It is given as peak to peak voltage. DC voltage components on the sensing element are not allowed.
The HC sensors can operate within the specified frequency limits. For best results we recommend an operating frequency of 20 kHz. All specified technical data are measured at an operating frequency 20 kHz.
|Based on the high-end HC1000 and HC101, HC103 was developed to meet the demands of automatic assembly lines for mass production at a competitive price. Typical applications are automotive or home appliances. HC103 sensors are positioned on the PCB at the same time as other SMD components and soldered using the reflow soldering method. Their small dimensions allow an easy and space saving design. They show the same excellent measuring characteristics as HC1000 and HC101, such as high reproducibility of the sensor data and outstanding linearity over the whole humidity range. The temperature dependence is also highly reproducible and allows software temperature compensation. This means high accuracy over a wide temperature range, which is essential for instance to calculate dew point temperature.|
|HC104-Inter changeable SMD Version|
|HC104 is the latest development of the well proven HC103 SMD-mounted sensor. Additionally to the HC103 features, the dispersion of nominal capacity of HC104 is reduced to a minimum by a special laser trimming process in a lot of applications. Time consuming humidity calibration is not necessary any longer. The result is an interchangeable sensor with excel-lent price/performance ratio, ideal for mass production in automatic assembly lines.|
|HC201 cost-effective applications|
|HC201 is the ideal solution for large volume cost-effective applications in indoor climate control. The version with plastic housing, HC201/H is available for easy manual mounting on PCBs.|