## 1 Introduction  
Dust and gas explosions are among the greatest disasters in the coal industry and are related with mass fatalities. This is a danger for the entire mining industry, not just coal mining [1]. In this regard, safety improvement during blasting operations in gaseous and dusty mines is of utmost importance [2]. Dust-methane explosion safety upgrades are possible only by a comprehensive approach, including risk management [3; 4; 5], development of tools and methods of mine explosion protection, methane emission control [6], coal deposits underground mining technological processes monitoring [7; 8; 9; 10].  
Among the effective ways to control possible explosions are the automatic ignition prevention systems. The sensors applied in automatic explosion barriers respond to high pressure (outside rods) and temperature, abnormal concentrations of explosive gases, optical parameters and flames [11]. The disadvantage of the sensors, responding to the explosion wave pressure, is their possible actuation because of extraneous acoustic signals. The authors of [12] provide an explanation of the outside rods' inefficiency due to their spatiotemporal parameters that are insufficient for successful explosion containment. The disadvantage of sensors, responding to the temperature changes, is their sensibility to the dusty mine environment, dust deposits, etc. [13]. Since the ignition process includes lighting, the perfect solution is optical sensors detecting dynamics in infrared and ultraviolet radiation and able to start the automatic prevention system to avoid combustion and explosions of methane-dust-air mixture.  
The first thing we consider when estimating occupational injury risks is the air shock wave produced by methane-dust-air mixture's explosion [9]. Therefore, it's clear that an effective suppression system should be started at the very early ignition stages [14; 15; 16]. For this reason, the optical sensor's spectral response should be sufficient to start the suppression system.  
There is one method [17; 18] to measure object temperature without known emittance involvement. However, this method is not effective because of its slow response, due to the need to analyze and process a wide range of the optical spectrum [19]. In this regard, the correct choice of optical sensor is impossible without considering a specific flame and methane-dust-air explosion radiation spectrum.  
A number of optoelectronic devices (OEDs) have been proposed for use in fire detection and localization systems, including two spectral ratio optoelectronic devices. The device uses radiation in three spectral ranges (750 \(\pm\) 40 nm, 950 \(\pm\) 50 nm, 1550 \(\pm\) 12 nm). However, the study does not give a criterion for the choice of these ranges [20].  
Moreover, for proper extinguishment within the development ratio with a cross-sectional area up to 10 m\({}^{2}\), it is necessary to create the explosion-suppressing environment by throwing out at least 30 kg of inhibitor within 15 ms. This throwing rate in case of false alarms can be dangerous for people located in the immediate vicinity to the explosion suppression devices [21].  
Therefore, the development of construction and creation of a fast-operating OED control of explosive dust and gas atmosphere, insensitive to dustiness of the intermediate atmosphere and having a high probability of detecting the ignition source at an early stage in the presence of external optical interference, is an urgent scientific and technological task. It has an essential economic importance.  
Thus, this research aims to obtain the spectral characteristics of combustion and methane-air mixtures' explosion radiation for the correct choice of input sensors applicable for explosion suppression systems.