From what I could gather from the docs:
value
is the value of the measure. This needs to be used in conjunction with the unit
parameter to get the correct value.
type
indicates the measure type. In this case, 12 means temperature
unit
is the exponential multiplier which needs to be multiplied with the value field to get the actual value in SI units.
Formula:
actualValue = value * (10 ^ unit)
Breaking down one of your examples:
{ value: 26918, type: 12, unit: -3 }
Here type is 12 so it's temperature (consequently, we can assume the units to be Kelvin if the API returns in SI units)
so, actualValue = 26918 * (10 ^ -3)
which is 26.918K
The docs don't explicitly mention what the temperature units are. I have assumed it to be Kelvin because that is the SI unit of temperature. Excerpt from docs:
Value
Value for the measure in S.I units (kilogram, meters, etc.). Value should be multiplied by 10 to the power of "unit" (see below) to get the real value.
Unit
Power of ten the "value" parameter should be multiplied to to get the real value. Eg : value = 20 and unit=-1 means the value really is 2.0