Humidity Data Logger Calibration Services

Relative humidity measurement

The relative humidity sensors are used to control comfort by HVAC ventilation control, ensure storage conditions in the food industry, monitor manufacturing processes in the pharmaceutical industry, monitor environmental variations in meteorology or even perform tests of mechanical resistance on test benches for the aerospace and automotive industry. If the relative humidity measurements are democratizing this is due to two factors: on the one hand because the industrialists seek to improve the quality of their products or the storage of foodstuffs / drugs and on the other hand because for 20 years the technology has evolved incredibly. In fact, if relative humidity was measured with psychrometers or hair hygrometers or mechanical instruments only a few decades ago, now the sensors manufacturers offer electronic hygrometers with the capacitive technology with much higher measurement accuracy.

Why is it necessary to calibrate a hygrometer?

Even though the quality of the relative humidity sensors and transmitters or standalone recorders (data loggers) is improving, they may be subject to drift due to the intrinsic quality of the sensor or due to the conditions of use. Therefore it is necessary to periodically monitor the behavior of measuring instruments by establishing services and calibration campaigns. For this, the metrologist can compare the measurement with a reference hygrometer connected to the national standards. The disadvantage of this method is that only one measuring point is controlled.

It can also send the measuring instruments in an accredited calibration laboratory and in accordance with the international standard ISO 17025 but in this case it undergoes a period of immobilization of the production sensor. Nevertheless, there is an alternative that consists of the use of a portable humidity generator in order to recreate relevant process condition. In addition to broadening the spectrum of calibration (operating range), a high-performance humidity generator, such as the HG-101, will also be able to evaluate linearity, response time, repeatability and stability measurement of relative humidity calibrator & transmitters operated in production.