DEVELOPMENT OF A PROGRAM FOR CALCULATING THE PREDICTED OPERATION TIME OF GAS FILTERS

Objective: Development of software to calculate the predicted duration of protective action of gas filters for gas masks and respirators under specific operating conditions. Methods: The program for determining the predicted breakthrough time of gas filters was created using the integrated development environment Visual Studio Code. The algorithm embedded in the program is based on the mathematical equations of Wheeler-Jonas and the conversion of concentrations of chemical compounds into different dimensions. The real breakthrough time of gas filters was established on a laboratory stand for determining the absorption capacity, which meets the requirements of DSTU EN 14387:2021, and also provides the opportunity to use four test substances during testing, such as cyclohexane, sulfur dioxide, hydrogen sulfide or ammonia. Results: A software package was developed to calculate the predicted breakthrough time of gas filters for gas masks and respirators under specific operating conditions. It consists of four modules: initial data input, memory, output and visualization of information, and calculation of breakthrough time of gas filters. An algorithm for calculating the predicted level of filters breakthrough time was developed, which includes five steps: determining the hazard, concentration of harmful substances, required respirator protection class, humidity and air temperature, mode of operation; entering initial data for calculation; preliminary selection of a filter from the specified catalog located in the memory module; calculation of filter capacity and analysis with permissible values of the chemical substance with the calculation of breakthrough time; visualization of results and their storage in the memory module. Novelty: Establishing the dependency of the predicted breakthrough time of FRPA-G A1, B1, K1 filters on varying concentrations of chemicals in the air and the type of work performed, which allowed identifying a five-fold reduction in filter operation time during heavy work compared to light work. Practical Value: Results obtained by comparing the predicted breakthrough time using the developed software product with the programs of personal protective equipment manufacturers showed an error not exceeding 10%, due to the lack of accounting for uneven wear of the filter filler across its surface. Keywords: adsorption, gas filter, software, breakthrough time, substance concentration.