White Paper: Focus on humidity elements and modules

Innovative Sensor Technology (IST AG): Humidity measurement is nowadays crucial for most applications in the industry. The application range for humidity sensing include industrial process control, food storage & refrigeration, t&m, HVAC, medical & healthcare as well as automotive. These are only a few examples where humidity measurement play a vital role in our lives.

Humidity Measurement Applications with Outstanding Stability

Often, humidity needs to be carefully balanced. Small variations in the relative humidity content in applications such as breathing air controllers (anesthesia), could result in nausea of the patient or even impact the anesthetic result.

The most critical tasks in humidity measurement are a stable detection of a proper humidity level with an acceptable response time. Coverage of the full measurement range from 0 % RH to 100 % RH is mandatory. Needless to say, stability should remain unchanged, even if operated under elevated conditions over years.

Temperature and environmental aspects of the individual application have significant impact on the long term stability requirements. Often, humidity sensors show their weaknesses when it comes to high or low humidity, temperature cycling or when exposed to aggressive chemicals.

P14
The standard P14-W humidity sensor was developed to satisfy the wide range of applications in HVAC, test & measurement, white goods and in industrial fields and is optimal for various application needs - available with wires and as SMD.

P14 Rapid
Within meteorology applications, such as radio sondes and weather balloons, there is a strong need for ultrafast, stable and robust humidity sensors. Not only at normal conditions, but also under elevated environmental constraints as extreme low temperatures, high radiation levels and under extreme condensation, the whole sensor operation has to be granted. Such applications need fully tailored solutions, such as those provided by the P14 Rapid.

P14 2FW Thermo
The P14 2FW Thermo was designed specially for applications in dew point applications and humidity generators. The favourable one chip solution consists of a capacitive humidity sensor, based on the famous P14 sensor, together with a heating element, which is also a valid Pt100 or Pt1000 sensor, at the same time. The achieved outstanding measurement accuracy due to optimal thermal coupling makes your application cutting edge in the industry.

P14 FemtoCap (SMD)
Despite its very small size, the FemtoCap has excellent sensor characteristics that are required in areas such as automotive and white goods. In combination with external electronics, it offers an excellent cost to performance ratio. The Femtocap is an optimal cost efficient sensor solution and currently P14 FemtoCap is one of the smallest capacitive humidity sensors on the market.

MK33
Our specially developed capacitive humidity sensor features a base capacitance of 300 pF. It is optimal for oil measurement applications and has a measuring range from 0 % RH to 100 % RH between -40 °C to +190 °C. The sensor is available with flexible or rigid connecting wires, making it the first choice for installation in detecting probes.

K5
With its small dimension and high sensitivity, the K5 was developed for applications where an accurate measurement in low humidity ranges were required. The sensor is characterized by the outstanding stability in low humidity, very low drift and a high chemical resistance. With its excellent sensor characteristics, the K5 is the optimal choise for low humidity environments.

Calibrated digital humidity and temperature modules

The newest members of the IST AG humidity familiy are the fully calibrated digital humidity modules, HYT, which combine the advantages of a precise, capacitive humidity sensor element with the high integration density and functionality of an ASIC.

With the integrated signal processing, the module completely processes the measured data and directly delivers the physical parameters
of relative humidity and temperature over the I2C compatible interface.

Both, the linearity error and temperature drift, are corrected “OnChip” through computation, assuring outstanding accuracy over a wide range of applications. The modules are fully interchangeable and the pins are compatible with commercial standards.

The consistent high quality from IST AG is ensured by the use of the P14 humidity sensor with a high performance polymer. The sensors are characterized by a high chemical resistance and an excellent long term stability in critical application areas with high humidity and after dew formation.

Measurements up to 190 °C and 100 % RH with external humidity and temperature sensor

The digital and analog modules (DigiPicco™ and LinPicco™ series) with external sensors present another contribution to customers, who have no own in-house electronic development and require a plug & play device, which can be easily connected to e.g. valve controllers or display equipment in a very cost effective manner. The combination of a LinPicco or DigiPicco module with an external sensor leads to an excellent accuracy whilst measuring very high temperatures and humidity. In this regard, IST AG offers multiple variations.

• Wire lenghts are offered up to 15 m, whereas 1 m is standard
• Distortion of signals and microclimate are non-existent
• The electronics are not exposed to high temperatures and humidity