The videos demonstrate 2D thermal gradient mappings based on two pairs of 50 µm x- an y- thin film thermocouple (TFTC) sensors. We investigate thin film thermocouples (TFTC) asthermal gradient sensors at the micro-scale and demonstrate two-dimensional dynamic thermal gradient mapping for features as small as 20 μm. Pairs of x-direction and y-direction thermocouples sense the thermal gradient while another calibrates the Seebeck coefficient as S = 20.33±0.01μV/K. The smallest detectable temperature difference is 10 mK, and the sensitivity is 0.5 mK/μm.

  • Sensors
  • Last Updated On: 
    Thu, 09/05/2019 - 17:32

    Early data was collected by technicians using mercury thermometers, where any variation in the visit time impacted measurements. In the 1940s, the construction of airports caused many weather stations to be moved. In the 1980s, there was a move to electronic thermometers that are said to have a cooling bias.

    Given this complexity, there are a range of organizations that collate climate trends data. The three most cited land and ocean temperature data sets are NOAA’s MLOST, NASA’s GISTEMP and the UK’s HadCrut.

  • Environmental
  • Last Updated On: 
    Thu, 11/08/2018 - 10:34
    Citation Author(s): 
    Lawrence Berkeley National Laboratory