What is Mean Kinetic Temperature in basic language?
If you have a set of temperature readings across a certain period of time, the Mean Kinetic Temperature across this period means effective average thermal value for this period. This temperature value is what the stored goods effectively feel during the mentioned time. This is not the arithmetical average of the readings.
Mean Kinetic Temperature is calculated for understanding the effects of variations in temperature for temperature-sensitive goods during storage and transportation.
A sample from our data logger in the image on the right side indicates the MKT value automatically generated in its report. Nowadays we do not need to calculate MKT manually. You can simply place a temperature data logger and the reports will automatically indicate the MKT value.
Have you wondered the difference between the Mathematical Average value and Mean Kinetic Value?
The calculation is different from the Average value which is the sum total of the values divided by the count of the values. The mean Kinetic value is slightly higher than the average value.
Example of application of Mean Kinetic Temperature
In layman’s language this is explained below:
As an example, with Free Excel software for automatic calculation of MKT of multiple data loggers, we will consider that medicine which has to be maintained between 2-8 °C is transported for 10 hours. A temperature data logger is kept inside the box for recording the temperature continuously. At the end of the transportation, the recorded temperature data is downloaded and verified. At this point suppose that the temperature has gone above 8 °C a couple of times and below 2°C a couple of times. As the medicine is always to be kept between 2 and 8°C, you are not sure whether the medicine is acceptable or not since the temperature has gone above 8°C a few times or below 2°C a few times for different durations. In this case, you can check the MKT value of the 10 hours period and if the MKT value is within 2-8°C, the medicine is still considered to have retained all its properties.
Hence MKT for a substance can be defined as the calculated value derived from the complete recording over a specified period of time. If this value is within the permitted values, the substance is still considered to be safe.
How to Manually calculate Mean Kinetic Temperature in Excel Sheet?
Would you be interested in the simplest way using an Excel sheet? All of you are familiar with Excel and hopefully, this will be the simplest calculation method.
You may download the free excel sheet which defines a function namely “MKT”. This function can be used similarly to any other function such as SUM, AVERAGE etc.
If you do not want to calculate manually, we encourage you to download the free Excel sheet
Manual calculation Step by Step
The step by step method of calculating MKT is as below:
- Convert °C to Kelvin by adding 273.15 to each reading.
- Calculate Delta H/(Gas Constant x Temperature Reading). Delta H =83.14472 kJ/mole & Gas Constant = 0.008314472 kJ/mole/degree.
- Calculate the sum of all results of Step 2.
- Divide the result of Step 3 by the number of readings.
- Calculate the natural logarithm of the result in Step 4.
- Calculate the numerator Delta H divided by Gas Constant.
- Calculate the result of Step 5 by the result of Step 6.
- Convert Kelvin to Degree Centigrade. This gives the MKT value.
First of all, you will download the data from the temperature data logger or temperature and humidity data logger. (MKT is applicable for Temperature only and not for Humidity) Assuming that the data is recorded at equal intervals, this is the formula for calculation of Mean Kinetic Temperature:
Delta H is the Activation Energy: 83.14472 kJ/mole
R is the Gas Constant: 0.008314472 kJ/mole/degree
Conversion of °C to K: Add 273.15
Now we’ll go step by step starting with the denominator, which is complex:
We have considered sample data with only six readings.
Step 1: Convert °C to Kelvin by adding 273.15 to each reading
The MKT value is always calculated in Degree Kelvin. If your readings are in°C or °F, the same has to be first converted to Kelvin. The resultant MKT value also will be in Kelvin, which then has to be converted back to your required units
Step 2: Calculate the following for each reading:
Delta H/(Gas Constant x Temperature Reading)
Both step 1 & 2 are detailed in the following:
Excel formula for above example for first reading
=Exp(-83.14472/(0.008314472 x 292.95)
Result =1.49714 E-15 for first reading.
Step 3: Calculate the sum of all results of Step 2
This is simple! Simply sum up all values in column G.
Excel Formula in the above example for step 3:
Result = 1.00339E-14
Step 4: Divide the result of Step 3 by the number of readings
In this example, the total number of readings is 6. So divide the above results by 6.
Excel Formula in the above example for step 4:
Result = 1.67232E-15
Step 5: Calculate natural logarithm of result in Step 4
Excel formula in the above step is
=(LN(SUM(G11:G16)/6)) x -1
Step 6: Calculate numerator
The numerator is Delta H divided by Gas Constant.
Step 7 : Calculate numerator by the denominator
Result = 293.903
Step 8: Convert Kelvin to Degree Centigrade
Excel calculation method:
Result= 20.7530 °C
Hence the MKT value is 20.7530 °C.
Free Excel Template Sheet for calculating MKT
All the data has to be listed vertically. At the end of the last cell simply insert the formula =MKT(B1: B100). This will produce an MKT value of the range of values from B1 to B100. There is no limitation to the range and you may include any number of data. Simply replace the range B1: excelB100 with your corresponding range.
This excel sheet also calculates Minimum, Maximum, Average values of the range of temperature values.
Should you require any clarification on the same you may please contact us.
Explanation of formula for Mean Kinetic Temperature (MKT)
The calculation method is a bit complicated as below. Look puzzled? Go to the Excel sheet above and do it by simple means.
The calculation formula for MKT is explained below. This formula is already incorporated in the Excel sheet above.
Short form of the formula for MKT
Detailed formula for calculation of MKT
Do you find the above calculation to be tough? Please feel free to Download the free Excel sheet!!
Temperature Dataloggers with inbuilt MKT value calculation
We supply various types of data loggers which have an inbuilt calculation of Mean Kinetic Temperature. Our Temperature data loggers, as well as Temperature and Humidity Data Loggers, give the MKT value of the complete readings as part of the report. The MKT value is calculated from the first reading to the last reading. So when you receive a box of medicines, you can download the data from the temperature data logger and check individual values as well as the MKT value. A sample report of one such data logger is given in this image.
How to use MKT for GDP applications?
MKT is commonly used in the storage and transportation of medicines, vaccines etc. The common applications are listed below:
- When medicine is stored in a warehouse or any storage facility, there might be temperature fluctuations. Assume that when you accept the goods, the temperature recorded till then was in perfect condition and you shifted to your storage. You might use a new data logger and commence recording. A few days or weeks later, you take the medicine for onward despatch. At this point, you first check whether the temperature has been always within the limits. You find that the temperature exceeded a few times beyond the limits. In such a case, you will check the MKT value to decide whether it is usable. If the MKT is within the limits, then medicine is assumed to be good.
- Similarly, during transportation of medicine through various modes such as air, truck etc. At the end of the journey, you might notice that a few temperature escalations happened during the journey. Hence you will check the MKT before accepting or rejecting the goods.
This is a regular practice that was commonly practised until a few years ago. Now various local authorities and medicine manufacturers do not accept MKT as a standard practice. Hence you may check before completely going by the criteria of MKT.
How to use data loggers for calculating MKT?
We will consider few examples of calculation of MKT using data loggers.
- For transporting a box containing medicine, you have to keep a temperature data logger inside the box. As soon as you keep the medicine inside the box, start the data logger and keep it inside the box. Then you can dispatch the box. When the user receives the box, he will take the data logger and download the data. Then generate the pdf report. The report will show the MKT value as in this image to the right side.
- If you want to find out the MKT inside a cold room, you may keep Temperature and Humidity data loggers at the hot and cold points. If you want weekly data, you can start the data logger at the beginning of the week. You may keep a start delay of 10 minutes so that the recording settles down. At the end of the week, download the data and you may see the MKT value in the report.
- Another application is for finding out MKT inside refrigerators (medical fridges). If you want monthly data calculation, you can keep the data logger inside the refrigerator after starting at the beginning of the month. At the end of the month, download the data and see the automatically generated report to see the individual readings and the MKT value.
Real-Time Monitoring Temperature and MKT during transportation
With the technological advances, it is now possible to monitor MKT during the transportation of medicines. So during transportation, it can happen that temperature continues to increase, but the MKT continues to be within the limits. In such a case, you can take corrective actions if you have such real-time monitoring systems. If you have multiple boxes inside a refrigerated van, you can have monitoring sensors in each box. So you can monitor each box separately. The wireless monitoring system by Roambee provides such a monitoring system: https://blog.roambee.com/supply-chain-technology/mean-kinetic-temperature-mkt-calculation-should-be-real-time
How to use our Excel Calculation Sheet?
The entire calculation explained above is programmed in the excel sheet. If the readings are in Degree Centigrade, you have to simply use the function =MKTc after marketing the desired range. This function is exactly similar to the usage of =SUM in Microsoft Excel. If your readings are in Degree Fahrenheit, you have to use the function =MKTf. It is that simple.
FAQ on Mean Kinetic Temperature (MKT)
- What is Mean Kinetic Temperature?
If a temperature-sensitive product is stored across different temperatures in a specific range of time, MKT calculation gives an idea of the effects of temperature on this product.
- How to calculate Mean Kinetic Temperature (MKT)?
In order to calculate MKT, we need temperature measurements at regular intervals. We calculate MKT over a specific period. Then we can use these data in the MKT formula to calculate the effective MKT.
- MKT is applicable for which type of products?
Mean Kinetic temperature is applicable for any temperature-sensitive products. The major application is in the Pharma industry during storage of medicines, vaccines etc.
- How to use Excel for calculating Mean Kinetic Temperature?
MKT is calculated as per a mathematical formula and hence we can definitely use Excel for the same. We have designed an Excel calculation sheet in which you have to simply insert the recorded data.
- What is the purpose of calculating Mean Kinetic Temperature (MKT)?
We will consider medicine that requires storage between 2 to 8 Deg C. During storage and transportation of this medicine, it is possible that the surrounding temperature went above 8 Deg a number of times. Also, it is possible that the temperature went below 2 Deg C a few times. This can happen due to power outages, exposure to the sun during handling etc.
Your data logger records this data including the duration of such variations. Now you need to calculate whether the variations caused damage to the medicine or whether its efficacy is compromised. The manufacturer of the medicine specifies that the medicine is safe to use if the MKT of the entire duration is between 2 to 8 Deg C. Thus if the MKT is between 2 to 8 Deg for the duration, this means that the medicine is safe to use in spite of the temperature variations.
So if the medicine is shipped from the UK to Japan, the consignee at Japan will check the MKT of the entire duration before accepting the consignment. (This article is to be used only as a guideline. Please check with the medicine manufacturer for exact requirements.)
Revision history of this Excel calculation tool:
- Rev 0, 17-Feb-2014: Original version
- Rev 1, 13-Oct-2014: Separate sheet added for Fahrenheit & published online
- Rev 2, 23-Feb-2015: ΔH & R defined in the first two sheets
- Rev 3, 09-Mar-2015: Formatting changes only
- Rev 4, 15-May-2015: Formatting changes only
- Rev 5, 25-Jun-2015: Formatting changes only
- Rev 6, 25-Sep-2017: Major changes for increased functionality. The full & free version now made available online.
- Rev 7, 06-Feb-2018: Formatting changes only
Also please see our article: Is MKT still relevant for Pharmaceuticals? How will MKT misguide you?
Please visit our online data logger store for all types of data loggers.