Mean Kinetic Temperature
Some products and materials have accelerated rates of degradation at higher temperatures. For example, perishable food items and pharmaceutical products can degrade and many forms of bacteria grow exponentially as the environmental temperature increases. Mean kinetic temperature is a calculation that accommodates the non-linear thermal effect, which temperature can have on products. Mean kinetic temperature is represented as the equivalent temperature the product was thermally subjected to during the time the various temperature readings were recorded.
Mathematically the formula for calculating the mean kinetic temperature can be expressed as illustrated.
Formula for mean kinetic temperature
|
mkt |
is the mean kinetic temperature, in degrees Celsius |
|
ΔH |
is the activation energy. |
|
R |
is the the universal gas constant, which is 0.0083144 KJ/mol K |
|
n |
is the number of data points to include in the calculation |
|
ti |
represents the data points to include in the calculation, in degrees Celsius |
For example, if there were 5 data points of which to calculate the mean kinetic temperature, they were, 12.3, 15.9, 16.2, 14.7 and 14.9 degrees Celsius, then the mean kinetic temperature would be 14.9 degrees Celsius using the default ΔH.
By default LogTag® Analyzer uses an activation energy value of 83.144 KJ/mol for the calculation.
To enter a custom value for ΔH, click Options from the Edit Menu, then navigate to the Summary Statistic section where you can enter the desired value in the Use the following value text field.
Charts and the Statistics page display the ΔH parameter if it is different to the default value, and display Logger deltaH if the parameter from the logger was used.