Measurement instrument, relative humidity and temperature probe

In by solarsimulator-admin

Product Name: HMP 155 temperature probe
Test Method: Effect of UV radiation, accelerated testing
Client: Vaisala Oyj
Test Result:

The sheen of the plastic casing materials was reduced; similarly, colour changes were also visible. The mechanical properties were well preserved, in some cases even unchanged. No visual changes could be observed in the seals or Teflon filters. In normal operating conditions, the energy of UV radiation accumulated in the samples during the testing accumulates over 20-30 years for the HMP-155 probe.

Test Purpose:

The testing examined mechanical and visual changes caused by the sun’s UV radiation to the materials of HMP155, a humidity probe for outdoor use. The materials and testing samples were casing materials and seals from the sensor’s humidity probe. When used normally, the materials remain constantly in outdoor conditions: not in direct sunlight but in the shade created by a radiation shield.

Test Method in Detail:

The samples were subjected to a stress by UV radiation that resembles the sun’s UV radiation. In addition, the test was accelerated by increasing the radiant power to double it in comparison with that of a sunny summer day. Between the UV stages, the samples were sprayed with water. The samples were subjected to colour and gloss measurements as well as to measurements of pulling strength during the test. The total duration of the test was 1 000 hours (6 weeks).