In immersion and penetration measurements, the temperature probe is inserted directly into the measurement object. The measurement is finished as soon as the t99 time is reached.
Avoiding measurement errors – Tips for correct measurement
The most common measurement errors
If the temperature probe is colder than the measurement object, then energy in the form of heat is withdrawn from the measurement object in the vicinity of the probe. If it is warmer than the measurement object, then heat is introduced to the object. The mass ratio of the probe and the medium should also be taken into account: The greater this is, the more energy is withdrawn from the measurement object. Since this energy withdrawal means that the actual temperature of the object is no longer measured, a too high mass of the probe can lead to measurement errors.
- The penetration or immersion depth should be the 10 to 15 times the diameter of the probe.
- For immersion measurements in liquids, the liquid should be kept constantly in motion.
- In the ideal case, t99 is reached after approx. 0.5 seconds.
- Place probe tip flat onto surface.
- Do not move the probe during the measurement.
- Apply constant and sufficient pressure.
- Use low-mass surface probe.
- In the ideal case, t99 is reached after approx. 3 seconds.
- Use air probe with exposed sensor (not penetration or surface probes).
- Move the probe at 2 m/s during the measurement.
- Hold the probe away from your body.
- Use radiation-protected probes.
- In the ideal case, t99 is reached after approx. 7 seconds.