Calorie (IT) per Second per Square Centimeter [cal(IT)/(s·cm²)]

The unit calorie (IT) per second per square centimeter, written as cal(IT)/(s·cm²), measures heat flux density or power per unit area. It represents the amount of International Table calories (1 cal(IT) = 4.1868 J) transferred through 1 cm² of surface every second.

This unit is often used in laboratory-scale heat transfer experiments, solar energy studies, and radiation measurements, especially when dealing with small surface areas where the calorie is convenient. Applications include:

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  Measuring solar energy intensity on small surfaces

  
  
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  Calorimetry experiments on samples

  
  
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  Laser or focused radiation studies

  
  

The heat flux can be expressed mathematically as:

where q is heat flux in cal(IT)/(s·cm²), Q is energy in calories, A is area in cm², and t is time in seconds.

Conversion to SI units:

While W/m² is the SI standard, cal(IT)/(s·cm²) is convenient for small-area, high-intensity heat measurements in laboratory or historical contexts.

Calorie (th) per Second per Square Centimeter [cal(th)/(s·cm²)]

The unit calorie (th) per second per square centimeter, written as cal(th)/(s·cm²), measures heat flux density or power per unit area using the thermochemical calorie (1 cal(th) = 4.184 J). It represents the amount of heat energy transferred through 1 cm² of surface every second.

This unit is commonly used in laboratory-scale heat transfer experiments, solar energy studies, and focused radiation applications, especially where the energy is concentrated over a small surface area. Applications include:

• 
  

  Solar radiation intensity measurements

  
  
• 
  

  Laser or concentrated light experiments

  
  
• 
  

  Calorimetry experiments on small samples

  
  

Heat flux can be expressed mathematically as:

where q is heat flux in cal(th)/(s·cm²), Q is energy in calories, A is area in cm², and t is time in seconds.

Conversion to SI units:

While W/m² is the SI standard, cal(th)/(s·cm²) remains useful in laboratory and historical references, providing a practical measure for high-intensity, small-area heat transfer.