Chemical- physical analysesFurther investigations
The examination parameters and the examination intervals depend on the customer-specific question. The subject of the services is therefore also the targeted advice regarding the optimal examination program.
Gas evolution of insulating liquids and materials
New developments of materials (e.g. insulating liquids, paper, adhesives, resins, coatings, …) for electrical high-voltage devices, but also the thermally higher load possibilities of these devices can significantly influence the trend of analysis parameters. Investigation projects of VUM have shown that certain insulating liquids and materials can produce gas which is not related to thermal-electrical faults. These lead to changes in the gas pattern from the “gas-in-oil analysis” (Dissolved Gas Analysis, DGA), which makes accurate assessment significantly more difficult. In order to understand gas formation tendencies depending on the type of insulating oil and to be able to take them into account in the assessment, so-called stray gassing tests are carried out in accordance with the applicable standards.
We offer analytical dissection and sampling of craft paper samples from discarded transformers. In particular, the degree of polymerisation of the paper and the furan content of the paper and insulating oil are then determined in the laboratory in order to be able to make statements about the actual aging status of the insulating media. From the post-mortem examinations, in combination with further chemical-physical analyses, we gain essential findings for the existing collective of devices (service life).
VUM’s services include the analysis and assessment of lubricants.
The line portfolio includes the investigation and monitoring of diesel and petrol fuels. The assessment is based on the recognized standards EN 590 for diesel fuel and EN 228 for petrol.
Material and concrete testing
VUM carries out sampling and chemical-physical analyses of cement and rocks for concrete production as well as of sediments and soil.
Metallography (qualitative and quantitative structural analysis)
- On-site inspection (ambulatory component metallography)
- Analysis in the laboratory (determination of the phase fractions, grain size determination, determination of the degree of purity, weld inspection, investigation of damage cases)
- Magnetic test (MT), crack test
- Dye penetrant testing (PT)
- Visual examination (VT)
- Hardness testing on site and in the laboratory using a mobile hardness tester
- Wall thickness measurement (ultrasonic testing)
The scope of services includes sampling and analysis of ultrapure water, process water, water from cooling circuits, wastewater as well as ground and surface water.