The measurement of the racing tire temperatures in the motorsport races is one of the most important aspect in the management of tires performance. The best mechanical grip of racing tire is ever in a narrow operating window and is fundamental to be able that the tread works in the correct temperature range for its maximum performance.
Operating below or above the temperatures window it can cause a drop of tire performance. Using an accurate Tire Temperature Pyrometer can help the team in the tires approach management.
It is possible to measure the temperature of the tires using two different types of instrument:
Non-contact Temperature measurement
This category includes the Infrared pyrometer where the temperature is measured at a certain distance from the object to be measured.
Contact Temperature measurement
This category includes the Tire Pyrometer with needle probe where the temperature is measured by the contact between the instrument and the object to be measured.
Both solutions are precise in terms of accuracy; the only different thing is the way of measuring. With the needle probe pyrometer we can measure the temperature of the compound in specific points while with the infrared pyrometer we can measure the surface temperature of the tread.
Let’s now evaluate how to optimize the tread temperature measurement with the Infrared Pyrometer. This kind of instrument uses an electrical sensor that converts the infrared radiation emitted by a body having a certain temperature greater than 0K (-273 C) into an electrical signal.
The advantages of infrared technology in measuring the temperature of the tires are:
- response time ( 0.25 second );
- accuracy ( +/- 0.5 °C );
- ability to measure the average temperature of the entire tire tread.
One of the main disadvantages of infrared sensor technology is that it measures the surface temperature of the tread; it is not possible to measure the temperature of the compound as it is possible to do with the needle tire probe penetrating inside the compound.
One of the main questions received is: what is the optimal distance between the instrument and the tire tread in order to have the best measurement of the tire temperature?
Before answering this question it is essential to understand the FOV (Field Of View) parameter of the IR sensor.
What is the FOV ?
It is the angle within which the sensor is sensitive to infrared radiation emitted by the object to be measured.
The measured temperature will then be equivalent to the average of all objects within the FOV.
It is therefore fundamental that the object to be measured or its portion will be completely enclosed within the FOV.
In this video you can clearly understand how the temperature measurement develops as a function of the FOV.
All models of Prisma Electronics digital tire pyrometer with infrared sensor have on the display the symbol of the spot from which the infrared radiates so as to easily understand the point where to measure.
What is the correct distance between the instrument and the tire to be measured ?
Distance between the instrument and the tread to be measured is directly related to the parameter of the FOV. The infrared pyrometers of Prisma Electronics have a 35° FOV.
The graph shows how the surface hitting the tire increases (Spot) according to the distance with the instrument.
- Distance Tire tread – Pyrometer = 25 mm –> Spot size +/-22mm
- Distance Tire tread – Pyrometer = 75 mm –> Spot size +/-66mm
This can represent an advantage of the temperature measurement without contact with the infrared sensor; it is possible to choose the width of the tire surface that we want to measure by moving the instrument away or closer.
Tire pressure and temperatures measurement with combo instrument HPM4 + PYR2-IR + STW
Tire pressure gauge with infrared sensor pyrometer and Stopwatch –> Click here
Tire pressure gauge with infrared sensor pyrometer –> Click here