30TH DAAAM INTERNATIONAL SYMPOSIUM ON INTELLIGENT MANUFACTURING AND AUTOMATION DOI: 10.2507/30th.daaam.proceedings.153 RESEARCH OF THE INFLUENCE OF EXTERNAL FACTORS ON THE MEASUREMENT OF A BASIC SOIL QUALITY PARAMETER Tsvetelina Georgieva, Sechkin Remzi, Nadezhda Paskova, Emil Stefanov, Nikolaos Sigrimis & Plamen Daskalov This Publication has to be referred as: Georgieva, T[svetelina]; Remzi, S[echkin]; Paskova, N[adezhda]; Stefanov, E[mil]; Sigrimis, N[ikolaos] & Daskalov, P[lamen] I[vanov] (2019). Reasearch of the Influence of External Factors on the Measurement of a Basic Soil Quality Parameter, Proceedings of the 30th DAAAM International Symposium, pp.1097- 1101, B. Katalinic (Ed.), Published by DAAAM International, ISBN 978-3-902734-22-8, ISSN 1726-9679, Vienna, Austria DOI: 10.2507/30th.daaam.proceedings.153 Abstract The paper presents a research of the influence of external factors on the measurement of a basic soil quality parameter. Developed system based on Arduino platform is used for measurement of basic soil parameter acidity. Research of the influence of temperature and soil type on the measurement of soil acidity is carried out. The system has been experimentally tested with soil samples from two main types of soil in Bulgaria. The results for the soil parameters obtained with the Arduino based system are compared with a reference measuring instrument. The presented Arduino based system for soil parameters measurements shows good measurement accuracy sufficient for engineering research. Keywords: Soil Acidity; Arduino platform; Reference measurement. 1. Introduction There are different types of soil quality analysis systems. Systems based on different soil analysis methods are presented. Spectral analysis offers many possibilities in soil analysis. It can detect the presence of very small quantities (10-11-10-12g) of an element. The intensity of the emitted spectral lines makes it possible to determine the amount of the element (quantitative spectral analysis). In recent years, experts have highlighted the benefits of spectral analysis in the infrared region as a quick alternative to simultaneously investigating several indicators. The development of instruments, and in particular the ability to use optical fiber instruments, allows samples to be analyzed not only in specialized laboratories but also in the field [1]. The pH, content of organic carbon, content of absorbable forms of phosphorus and potassium can be determined. The InfraAlyzer450, Technicon is a filter spectrophotometer equipped with 19 fixed filters, allowing spectral data to be obtained at 19 wavelengths ranging from 1445 to 2348nm. FQA-NIRGun, Fantec, is a scanning spectrophotometer operating in the shortwave range of 600 to 1100nm. In both spectral apparatus, the sample spectrum is obtained by measuring the diffuse reflection from ground and homogenized samples and recorded as log (1 / R), where R is the reflection from the sample. The Technicon InfraAlyzer System Software quantitative analysis software is used to process - 1097 -