{"product_id":"2940013206670","title":"Propagation of EM Signals in Underground Mines","description":"This report is a comprehensive summary of the results of the propagation measurements program conducted for the Bureau of Mines. Data were gathered in the medium frequency (MF) range from a cross sample of six mines representative of the industry having typical wireless requirements. From the data that were gathered, a logical method of data reduction is presented that culminates in a set of average attenuation characteristics for all mines visited. These characteristics define a typical MF wireless system when the communication range requirements are known. Direct through-the-earth propagation and the range enhancement mechanism due to coupling on-and-off conductors are evaluated and related to the planning of a typical wireless MF communications system.","brand":"1001 Property Solutions LLC","offers":[{"title":"Default Title","offer_id":47068723675376,"sku":"2940013206670","price":6.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0737\/7593\/9824\/files\/2940013206670_p0.jpg?v=1763578229","url":"https:\/\/shop-qa.barnesandnoble.com\/products\/2940013206670","provider":"Barnes \u0026 Noble (DEV)","version":"1.0","type":"link"}