Novel Wood Resistance Measurement Method Reducing the Initial Transient Instabilities Arising in DC Methods Due to Polarization Effects
A novel method for measuring the electrical resistance in wood is presented. It is based on applying an Alternating Current (AC) to two electrodes rammed into the wood. The method reduces the transient time for value stabilization. In case of Direct Current (DC) resistance measurement methods, typic...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2019-11-01
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| Series: | Electronics |
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| Online Access: | https://www.mdpi.com/2079-9292/8/11/1253 |
| _version_ | 1811187844490723328 |
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| author | Silvia Casans Berga Rafael Garcia-Gil A. Edith Navarro Anton Alfredo Rosado-Muñoz |
| author_facet | Silvia Casans Berga Rafael Garcia-Gil A. Edith Navarro Anton Alfredo Rosado-Muñoz |
| author_sort | Silvia Casans Berga |
| collection | DOAJ |
| description | A novel method for measuring the electrical resistance in wood is presented. It is based on applying an Alternating Current (AC) to two electrodes rammed into the wood. The method reduces the transient time for value stabilization. In case of Direct Current (DC) resistance measurement methods, typically used in wood measurement, an initial transient exists, invalidating the measured value during an initial transient period. This measurement method uses an electronic circuit based on a relaxation oscillator where the wood automatically sets the oscillation frequency depending on its electrical resistance. Compared to other AC methods, this circuit greatly simplifies the measurement process, not requiring any previous analysis for wood AC frequency estimation. Experimental results for four different wood species showed that, in all cases, the transient response of the measured wood resistance is improved when compared to the DC resistance method, reducing the stabilization time from 10−12 min in DC measurements to almost zero for the novel measurement method. The deviation between the initial wood resistance measurement and the stable value resulted in a range between 0.2% and 5% with the proposed method, while a range between 6% and 10% was obtained when using the DC method. Moreover, the proposed circuit is able to detect changes in wood resistance produced by small variations in temperature and environmental relative humidity during continuous long term measurements. For repeatability analysis, it was verified that similar ambient conditions of temperature and relative humidity (variations lower than 1 °C and 1%, respectively) in different moments provided variations lower than 1.5%. The method can also be applied to other fiber materials affectd by polarization effects when an electrical current is applied into them. |
| first_indexed | 2024-04-11T14:10:22Z |
| format | Article |
| id | doaj.art-837b61e403094c2fb08bc5b7d6b4e884 |
| institution | Directory Open Access Journal |
| issn | 2079-9292 |
| language | English |
| last_indexed | 2024-04-11T14:10:22Z |
| publishDate | 2019-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Electronics |
| spelling | doaj.art-837b61e403094c2fb08bc5b7d6b4e8842022-12-22T04:19:45ZengMDPI AGElectronics2079-92922019-11-01811125310.3390/electronics8111253electronics8111253Novel Wood Resistance Measurement Method Reducing the Initial Transient Instabilities Arising in DC Methods Due to Polarization EffectsSilvia Casans Berga0Rafael Garcia-Gil1A. Edith Navarro Anton2Alfredo Rosado-Muñoz3Department of Electrical Engineering, School of Engineering, University of Valencia, Av. Universitat s/n, 46100 Burjassot, Valencia, SpainDepartment of Electrical Engineering, School of Engineering, University of Valencia, Av. Universitat s/n, 46100 Burjassot, Valencia, SpainDepartment of Electrical Engineering, School of Engineering, University of Valencia, Av. Universitat s/n, 46100 Burjassot, Valencia, SpainDepartment of Electrical Engineering, School of Engineering, University of Valencia, Av. Universitat s/n, 46100 Burjassot, Valencia, SpainA novel method for measuring the electrical resistance in wood is presented. It is based on applying an Alternating Current (AC) to two electrodes rammed into the wood. The method reduces the transient time for value stabilization. In case of Direct Current (DC) resistance measurement methods, typically used in wood measurement, an initial transient exists, invalidating the measured value during an initial transient period. This measurement method uses an electronic circuit based on a relaxation oscillator where the wood automatically sets the oscillation frequency depending on its electrical resistance. Compared to other AC methods, this circuit greatly simplifies the measurement process, not requiring any previous analysis for wood AC frequency estimation. Experimental results for four different wood species showed that, in all cases, the transient response of the measured wood resistance is improved when compared to the DC resistance method, reducing the stabilization time from 10−12 min in DC measurements to almost zero for the novel measurement method. The deviation between the initial wood resistance measurement and the stable value resulted in a range between 0.2% and 5% with the proposed method, while a range between 6% and 10% was obtained when using the DC method. Moreover, the proposed circuit is able to detect changes in wood resistance produced by small variations in temperature and environmental relative humidity during continuous long term measurements. For repeatability analysis, it was verified that similar ambient conditions of temperature and relative humidity (variations lower than 1 °C and 1%, respectively) in different moments provided variations lower than 1.5%. The method can also be applied to other fiber materials affectd by polarization effects when an electrical current is applied into them.https://www.mdpi.com/2079-9292/8/11/1253wood resistance measurementelectrical resistance measurewood polarization effectrelaxation oscillator |
| spellingShingle | Silvia Casans Berga Rafael Garcia-Gil A. Edith Navarro Anton Alfredo Rosado-Muñoz Novel Wood Resistance Measurement Method Reducing the Initial Transient Instabilities Arising in DC Methods Due to Polarization Effects Electronics wood resistance measurement electrical resistance measure wood polarization effect relaxation oscillator |
| title | Novel Wood Resistance Measurement Method Reducing the Initial Transient Instabilities Arising in DC Methods Due to Polarization Effects |
| title_full | Novel Wood Resistance Measurement Method Reducing the Initial Transient Instabilities Arising in DC Methods Due to Polarization Effects |
| title_fullStr | Novel Wood Resistance Measurement Method Reducing the Initial Transient Instabilities Arising in DC Methods Due to Polarization Effects |
| title_full_unstemmed | Novel Wood Resistance Measurement Method Reducing the Initial Transient Instabilities Arising in DC Methods Due to Polarization Effects |
| title_short | Novel Wood Resistance Measurement Method Reducing the Initial Transient Instabilities Arising in DC Methods Due to Polarization Effects |
| title_sort | novel wood resistance measurement method reducing the initial transient instabilities arising in dc methods due to polarization effects |
| topic | wood resistance measurement electrical resistance measure wood polarization effect relaxation oscillator |
| url | https://www.mdpi.com/2079-9292/8/11/1253 |
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