key: sensor_number-timestamp (rounded to seconds)
document: {1st number of 1st sec part: {1st num. of 1st subsec: [deviation, pressure], 1st num of second subsec: [deviation, pressure], ...},
           1st number of 2nd sec part: {1st num. of 1st subsec: [deviation, pressure], 1st num of second subsec: [deviation, pressure], ...}}

key:1407838200
document: {0: {0: "25 256", 1: "35, 255", ...}, 1: {0: "26 256", 1: "46, 255", ...},