Settings

Now showing1 - 10 of 11
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
    Self-oscillating measurement system for in situ-monitoring moisture in buildings
    (2014-12)
    Sokoll, Thorsten
    ;
    Jacob, Arne F.
    A compact and inexpensive microwave system for in situ monitoring the moisture content in concrete structures is presented. It consists of an active microwave sensor and a frequency meter. Both components and their integration are briefly described. To cover the vast moisture range of interest, the system is calibrated against the wet basis moisture content and the ambient (equilibrium) relative humidity. The system's suitability for the given task is evaluated under realistic conditions.
    Publicationtype: Journal Article
      39
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
    Sensitivity analysis of microwave sensors for the permittivity measurement of liquids
    (2009-04-21)
    Müller, Johannes
    ;
    Sokoll, Thorsten
    ;
    Jacob, Arne
    This paper presents an advanced microwave sensor for the complex permittivity measurement of liquids. By means of a rigorous mode matching technique, the sensitivity of the microwave sensor is analyzed and its structure is successfully optimized for the use at low frequencies.
    Publicationtype: Conference Paper
      76
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
      34
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
    Self-calibration circuits and routines for low-cost measuring systems
    (2008-02-01)
    Sokoll, Thorsten
    ;
    Jacob, Arne F.
    A Low-cost measurement system suited for in situ moisture monitoring of buildings is presented. The system consists of a robust and compact resonant microwave sensor linked to a miniaturized, low-cost vector network analyzer. Several such systems can be controlled by a central monitoring station. The measurement accuracy is enhanced significantly by vectorial self-calibration. To determine the magnitude and the required 360°-phase information, an inexpensive combined gain and 180°-phase detector is used, where the full phase information is obtained by adequately modeling the sensor's and the calibration standards ' phase response. Different self-calibration circuits are examined and their suitability is proved by comparative measurements. Finally, the system's performance is tested in a high humidity environment.
    Publicationtype: Journal Article
      44
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
    Broadband low-cost frequency meters
    (2008)
    Sokoll, Thorsten
    ;
    Jacob, Arne F.
    Two types of low-cost frequency meters for signals from several hundred megahertz up to 8 GHz are presented. The first system utilizes the well-known principle of frequency counters. The second one is based on a novel concept, where the frequency is derived from a direct comparison with a known reference. The two approaches are discussed and compared in terms of their principles and limits. Based on a statistical analysis of the results, this paper demonstrates the advantages of the novel concept for short measurement times.
    Publicationtype: Journal Article
      36
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
      32
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
    In-situ moisture detection system with a vector network analyser
    (IOP Publishing, 2007-02-27)
    Sokoll, Thorsten
    ;
    Jacob, Arne
    An in-situ measuring system for determining the moisture content in concrete buildings and masonry is presented. The system consists of a small and robust resonant microwave sensor and a compact low-cost network analyser. The sensitivity and frequency range requirements for the analyser are derived from the sensor design. A suitable realization of the analyser is discussed in detail. It is shown that a vectorial calibration routine diminishes measurement uncertainties caused by the used low-cost devices. Consequently, the moisture content can be determined within 0.6% instead of 3.0%. A test of the entire in-situ measurement system under realistic conditions is presented and discussed. © 2007 IOP Publishing Ltd.
    Publicationtype: Journal Article
      41
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
      43
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
    A self-calibrating low-cost sensor system for moisture monitoring of buildings
    (IEEE, 2006)
    Sokoll, Thorsten
    ;
    Jacob, Arne
    A low-cost measurement system for in-situ moisture monitoring in buildings is presented. Each unit of the system consists of a robust and very compact resonant microwave sensor linked to a miniaturized, low-cost vector network analyzer (VNA). A self-calibration network is implemented for improved measurement accuracy. Results are presented and compared to those achieved with a high precision laboratory network analyzer.
    Publicationtype: Conference Paper
      50
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
      47