In paper machines, heating is used to remove the water from the paper using steam-heated drying cylinders. These operate in an environment up to 80 °C with up to 90% humidity.

As well as water, steam etc. can directly enter the oil circulating system on the sealed labyrinths of the drying cylinder stocks. Fine lint can also penetrate the oil in circulation. Oil contaminated with lint and water ages significantly faster. It is no longer a reliable source of lubrication, produces corrosion e.g. on the bearing cage's non-ferrous metals, or creates gel-like deposits.

The oil circulation plant of a paper machine often holds more than 10,000 liters of synthetic oil. Oil analyses every three months allow oil use times to be optimised, helping reducing costs and care for the environment.

The hydraulics systems in modern injection presses are compact and high-performance. They are used around the clock. As the oil level rises and falls with the operating cycle, the tank "breathes". Even if this make-up air is filtered optimally, it may contain small quantities of plastic granules, gaseous impurities or moisture.

High temperatures and pressure, as well as wear particles, accelerate the ageing process of the oil used. If the viscosity changes as a result, this has an impact on the efficacy of the hydraulics.

Two to three analyses a year can ensure oil changes are carried out early, reducing downtimes and costs.

Hydraulic fluids from press systems in the steel, aluminium, wood and plastic industry are often contaminated with fine particles of the material used in forming, such as buffing paste, or the raw material, such as wood. In spite of ventilation filters and main and secondary flow filters, impurities may enter the oil and lead to abrasion of valves, causing internal leakage.

The oil temperature increases. The oil ages faster as a result. The hydraulic oil, which is contaminated, oxidised, or simply does not have enough additives, may ultimately lead to the forming press coming to a standstill.

Regular oil analyses every 2,000 hours allow the condition of the machine and oil to be monitored and avoid such breakdowns.

In the automotive industry, robots mainly take on tasks such as welding, painting and bonding.

This type of robot has one gear per axis. Each gear is filled with around 15 litres of gear oil. Due to this low quantity, routine lubricant analyses are not usually performed for all gears.

However, the high level of strain put on the oil by long-term use, the jerking motions and high gear temperatures, which are around 80 °C on average, is a good argument for regular oil analyses. This is the only way to prevent damage and resulting downtimes early.

Several thousand litres of oil are in use in large oil circulation systems, often for several years. The products of ageing oil form slight impurities over time.

Without careful monitoring by means of trend analyses, however, sludge-forming impurities and glutinous reaction products may go undetected for long periods of time. With the circulating oil, they can also reach coolers, tanks and filters.

"Varnish" can thus be deposited on control valves and plain bearings, and reduce the flow of oil or accumulate as oil sludge in oil-bearing pipes or in the tank. An oil analysis can recognise these impurities, enabling early remedial actions to be taken.

Heat transfer systems must be monitored. Supervision of the facilities also includes an investigation of the heat transfer oil at least once a year.

With long-term exposure to operating temperatures of around 250-300 °C, the oil must have good thermal stability and a high flash point and initial boiling point. Low viscosity and excellent thermal conductivity guarantee good heat transfer.

A high level of ageing stability and low tendency towards corrosion are also necessary for the heat transfer oil's long duration of use.

Changes in the oil may increase the risk of fire and cause damage to the facility.