What causes relative humidity sensor drift?

The gases in the environment will interact with humidity sensor, and may result in sensor drift.Water needs to be in and out of the sensor, which means that other gases can do it.In general, the strong smell is a substance is warning signal of evaporation.The use of cleaning products is one of the main causes of drift, especially the floor wax;Used for cleaning alcohol can lead to drift on the surface of the object.

In newly built houses, buildings and the new material and furniture, fixtures and equipment will release many solid or gas materials.Material storage area is another potential factor which causes the sensor drift, although a single package release amount of gas is very small, but may occur in the same position for a large number of packaging situation;Even in some cases, the packaging materials will also be a pollution source.For some humidity sensor, consider the influence of the dust, butVisa pull HUMICAP ® sensorsBasic is not affected by this, but because of its upper electrode will block the dust.

Humidity sensor drift will have performance?

When the humidity sensor are exposed to chemicals like floor wax, main effect is usually lower sensitivity.Chemicals that will occupy the internal space of sensors in the polymer, the polymer under normal circumstances is hydrophilic.The result is that polymer membranes ability to expand the number of water molecules downgrade, this means that under the environment of high humidity readings will be reduced.Another influence is under dry conditions measuring values may change;This effect for visa, HUMICAP ® sensor is usually small.In figure 1 below illustrates the drift of a typical example, which clearly shows the main effect for lower sensitivity.

Figure 1 contact with chemicals for the influence of humidity sensor readings

If you suspect drift is caused by chemicals, only under a humidity level check is not enough, because of its impact in this kind of humidity level (for example in figure 1. 30% RH) may be insignificant.

Corrosion is a completely different form of failure.It is rare in the normal office environment, but it will actually appear in places like swimming pool.Corrosion more worse than led to the incorrect reading sensors is given, it can lead to sensor failure completely.

How to deal with the drift?

If you're not sure how much your humidity sensor will be in contact with the chemicals, and these chemicals will have much impact on your measurement, pleaseContact our professional staffWe help you at any time.A new generation of visa pull HUMICAP ® sensors compared with the previous generation, enhances the ability of resistance to chemical pollution.If to uncertainties facing the situation, and existing problems of measurement is very important to the process flow, you may wish to consider using chemical removal function of sensor products, it will be regular heating humidity sensor chip, so as to remove pollutants.

What is important is that no matter what measure, no matter use what kind of measure instrument, the appropriate maintenance and regular calibration is necessary.Know more information about our calibration services.