Delta (Δ) is the fourth letter of the Greek alphabet and is used as a mathematical symbol. Here, the delta Δ describes the difference of any variable quantity.
Examples of variables are:
- Temperature
- Amount of substance
- Light intensity
T is the formula symbol for the physical temperature. With the designation of the temperature we describe the thermal condition of an object or a system. With it we express whether something is “cold” or “hot”. It is expressed in degrees Celsius (°C), degrees Kelvin (°K) or degrees Fahrenheit (°F). When these two pieces of information are combined, it is understood that Delta T (ΔT) stands for temperature difference.
Use of delta T (∆T)
In a thermal process, delta T (or ΔT) is the value that indicates the difference between two measured temperatures. These values can be measured at different locations or at different moments in a system. Three situations can be recorded:
- The temperature has not changed, it has remained the same
- The first value is smaller than the second value — temperature increase
- The first value is greater than the second value — temperature loss
Calculation of delta T (∆T)
∆T = T2 – T1
Practical examples of delta T (∆T)
Temperature differences can be determined in many applications. A typical example is the temperature profile in a cooling tower where the water is tested on the supply and return.
Unintended differences in temperature
Delta T (∆T) is an important measurement for monitoring temperature deviations and losses. Unintentional changes in temperature quickly have a negative impact on the functions in the system and should be identified and eliminated as soon as possible. For quick verification of temperature differences, data loggers can be used to record changes in the circuit and provide conclusions about the problem.
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