Trueness and precision of a method for determining the water content (%) of food and chemical products based on infrared radiation with a wavelength in the range (2.70÷7.21 μm) was evaluated. The most accurate measurements for food products were obtained when the heat source was a radiant heater with a radiation wavelength of 7.21 μm, a trueness deviation of 0.01%. When heated with radiation with wavelengths (from 3.32 μm to 7.21 μm), the trueness of the measurement ranged (0.03% ÷0.13%) for chemical products. The shortest analysis time for food products was found when the analysis was carried out using an IR source with a wavelength of 7.21 μm, while for chemical products, a heat source with a wavelength of 2.70÷7.21 μm was optimal. According to the results of the analysis, the use of IR radiation with a wavelength range of 3.32÷7.21 μm is an alternative for accurate measurements.

This work presents a method for measuring the magnetic susceptibility of soil samples based on interactions of magnetic particles contained in a tested sample with a weighed permanent magnet placed in the balance mechanical design. The MYA 2.4Y microbalance manufactured by Radwag Wagi Elektroniczne, Poland, was used to perform mass measurements. The weighing system was adjusted for mass indication using a certified mass standard, and for magnetic susceptibility indication using a certified magnetic susceptibility standard. The volume of each analysed soil sample was 3.93 cm ³ and was similar to the volume and the size of the magnetic susceptibility standard. The research was carried out for 10 soil samples with a magnetic susceptibility range varying from 20 to 1600x10 ^-8 m ³ kg ^-1. The soil samples contained technogenic magnetic particles and particles of natural magnetite of geogenic origin. The study was performed for a field of 2 mT.