3.1.2 Dual Sensor Setup for Thermal Mass Flow Sensor Diagnostics
- Event
- 16. GMA/ITG-Fachtagung Sensoren und Messsysteme 2012
2012-05-22 - 2012-05-23
Nürnberg, Germany - Chapter
- 3.1 Mechanische Sensoren: Druck + Durchfluss
- Author(s)
- D. Pape, K. Hencken - ABB Schweiz AG, Baden Dättwil (Schweiz)
- Pages
- 282 - 290
- DOI
- 10.5162/sensoren2012/3.1.2
- ISBN
- 978-3-9813484-0-8
- Price
- free
Abstract
For the flow measurement of gaseous flows thermal mass flow sensors are commonly used. They are based on a heat transfer measurement from a heated sensor into the fluid and provide precise mass flow measurements independent of the gas pressure. A critical issue for thermal mass flow sensors is the formation of coatings on the sensor head as they often occur in harsh environments. A coating will
change the thermal properties of the sensor and will thus strongly influence the flow measurement. An
accurate and stable measurement is therefore difficult to provide under harsh conditions.
In this study possibilities are thus investigated to detect the presence of coatings on the sensor head by using a dual temperature sensor setup. Here the thermal behavior of the sensor is investigated and
models are derived for describing the sensor and the influence of coatings. Based on these models
algorithms are developed to provide coating diagnostics for thermal mass flow sensors.