3 indispensable tips for accurate temperature measurement
Accurate and consistent temperature measurements are crucial for quality assurance of the final product in the pharmaceutical and food industries, while in other industries, they may be vital safety measures.
Temperature Measurement in Liquids
When measuring liquids, it is primarily important to use a liquid thermometer, which is designed to measure temperatures in liquids and other viscoelastic media.
A good rule of thumb to reduce any measurement uncertainties is to choose a temperature sensor with an immersion depth of about 10-15 times the sensor’s own diameter. If the liquid being measured is also in motion during the measurement, you are guaranteed to achieve the most accurate result.
Surface Measurements and Spot-Check
For surface measurements, one should always ensure that the sensor has good contact with the measurement surface, and the measurement point is representative of the entire surface’s temperature. It is also important to ensure that the contact surface being measured is not uneven, as this can affect the accuracy of the measurement.
However, one can often assume that any measurement uncertainties are within +/- 1◦C, as long as a calibrated instrument adapted to the temperature range being measured is used. Precise surface measurements can also, in many cases, replace invasive core temperature measurements.
Measurement of Air Temperatures
When measuring air temperatures, there are a number of things to keep in mind. In most facilities and buildings, the climate can change due to various external and internal influences – even if the building and facility are designed to compensate for such varying influences.
Therefore, it is always advisable to consider the variation in air temperature. Here, it can be helpful to ensure measurements are taken where experience shows the highest and lowest temperatures and the greatest temperature difference in the vertical direction. In most cases, measurements with an accuracy of 0.5-1 ◦C will be achieved.
